RIOT-2026.10 "GameOverBugs" - Release Notes

RIOT is a multi-threading operating system which enables soft real-time
capabilities and comes with support for a range of devices that are typically
found in the Internet of Things: 8-bit and 16-bit microcontrollers as well as
light-weight 32-bit processors.

RIOT is based on the following design principles: energy-efficiency, soft
real-time capabilities, small memory footprint, modularity, and uniform API
access, independent of the underlying hardware (with partial POSIX compliance).

RIOT is developed by an international open-source community which is
independent of specific vendors (e.g. similarly to the Linux community) and is
licensed with a non-viral copyleft license (LGPLv2.1), which allows indirect
business models around the free open-source software platform provided by RIOT.

About this release

The 2026.10 release includes:

Improved CoAP support with basic server (#21582) and client (#22266)
functionality of unicoap, the integration of the libCoAP library (#19889)
and the removal of unsafe and deprecated nanocoap APIs (#22505, #22861).
If you need to communicate with legacy non-CoAP endpoints out there, we've
also got you covered with the newly added integration of picohttpparser
(#22725).
We've got a new way of interacting with your favorite RIOT board: Jelly has
landed (#22634), offering a feature-rich shell interface with autocompletion
while reducing the binary size of your RIOT application.
Our 802.15.4 Radio HAL and (Sub)MAC implementation have received major
improvements (#21578, #21973, #22784, #22777) and support for two additional
radios: The AT86RF2XX family (#21674) as well as the KW41ZRF radio (#21992).
Three new boards have been added: STM32 Nucleo-G491RE (#22458), Seeed Studio
Xiao ESP32C6 (#22400) and the ZedBoard (#22548, our first board with
RISCV64!); while two boards have been deprecated: TelosB and Zolertia Z1
(#22716). We also got support for the mGBA emulator of the Game Boy Advanced
(#22776), which facilitated several improvements on this little fun device
(#22776, #22908).
The Docker container used for BUILD_IN_DOCKER=1 got a version update to
Ubuntu 26.04 Resolute Raccoon 🦝 (#22692) and the build system got many
smaller and larger optimizations to reduce the build time (#22898, #22355,
#22780, #22733, #22672, #22669, #22837, #22851 and more).
Our test infrastructure for CI, daily, weekly and release tests got cleaned-up
and hardened (#22787, #22653, #22954, #22671, #22956, #22960, #22942, #22958,
#22951 and more)

411 pull requests, composed of 792 commits, have been merged since the
last release, and 29 issues have been solved. 49 people contributed with
code in 70 days. 3025 files have been touched with 107371 (+) insertions and
38492 deletions (-).

Notations used below

+ means new feature/item
* means modified feature/item
- means removed feature/item

New features and changes

Core

byteorder.h: remove unused union members (#22622)

System Libraries

sys/base64: add ACCESS() attribute (#22369)
sys/fmt: add scn_bool() helper function (#22503)
sys/isrpipe: add isrpipe_get_free() (#22934)
sys/jelly: Add basic support for the Jelly tool (#22634)

rust: Update riot-sys and -wrappers (#22683)
sys/base64: minor improvements and documentation updates (#22383)
sys/can: annotate functions with ACCESS() (#22382)
sys/cpp_new_delete: handle allocation failures (#22418)
sys/hashes: minor improvements (#22386)
sys/include: Macro for ANSI Colours and Text Styles (#22621)
sys/isrpipe: fix isrpipe_write() return value documentation (#22453)
sys/shell/ifconfig: Give helpful error message when missing IPv6
support (#22689)
sys/shell: Initial bplib shell command (#22674)
sys/walltime: improve documentation (#22630)

Networking

drivers/kw41zrf: add support for IEEE 802.15.4 Radio HAL (#21992)
net/ieee802154/radio: add frame retention capability (#22784)
net/ieee802154/radio: add peek function (#22777)

net/ieee802154/submac: eliminate dead code (#22882)

net/unicoap: introduce optional inorder-only mode for options (#22535)
net/unicoap: Unified and Modular CoAP Stack: Client (pt 3) (#22266)
net/unicoap: Unified and Modular CoAP Stack: Messaging and Minimal
Server (pt 2) (#21582)
sys/net/ipv4: add MF/DF/reserved header constants (#22675)

sys/net/link_layer/ieee802154/submac: move ack transmission (#21973)
drivers/slipdev: Abort build if no auto init is selected (#22691)
drivers/slipdev: Replace nanocoap with unicoap (#22491)
ieee802154/at86rf2xx: port to Radio HAL (#21674)
ieee802154/submac: rework submac fsm logic (#21578)
net/gnrc/ipv6_ext_opt: fix reading of non pad1 options (#22517)
net/gnrc_netif: remove wait after send (#22721)
net/unicoap: Only import IP deps when in use (#22632)
pkg/lwip: fix dependency modeling (#22937)
sys/nanocoap: remove support for extended token length (#22505)
sys/net/gcoap: drop use of deprecated APIs (#22861)
sys/net/nanocoap: update users of deprecated API (#22859)
sys/net/nanocoap_cache: clean up code (#22858)

Packages

pkg/decadriver: move device configuration, add warnings, minor fixes (#22534)
pkg/decadriver: Port decadriver for dw3000 UWB chips (#22451)
pkg/libcoap: Add in libcoap CoAP library support (#19889)
pkg/picohttpparser: add package (#22725)
pkg/u8g2/contrib: allow setting display rotation (#22529)
pkg: Add missing SPDX (#22921)

pkg/bplib: Move Makefile out of patches (#22620)
pkg/ccn-lite: bump version which includes our patches (#22865)
pkg/esp32_sdk: use sparse checkout (#22837)
pkg/esp8266_sdk: use sparse checkout (#22841)
pkg/gecko_sdk: bump version (#22835)
pkg/micropython: incorporate port (#22350)
pkg/picohttpparser: update version (#22818)
pkg/u8g2: assert I2C buffer size before copy (#22442)
pkg/wolfssl: Update pkg to version that enables off the line pinning
for RPK (#22586)
pkg/wolfssl: upgrade to 5.9.2 and port the new upgrade (#22543)

Boards

boards/nucleo-g031k8: add I2C peripheral support (#22549)
boards/nucleo-g031k8: Add LED and button (SAUL) support for the
NUCLEO-G031K8 board. (#22421)
boards/nucleo-g031k8: add SPI peripheral support (#22479)
boards/nucleo-g491re: add support (#22458)
boards/seeedstudio-xiao-esp32c6: add initial support (#22400)
boards: add BMP as programmer for EFM32 boards (#22639)
drivers/periph/pdm: add PDM API and nrf52 driver (#22710)
makefiles: add mGBA emulator for gba_cartridge (#22764)
pkg/radiolib: add RadioLib as external package (#22271)

boards/stm32c0116-dk: enable cpy2remed (#22693)
cpu/stm32,boards/nucleo-h753zi: enable LPUART support (#22615)

CPU

cpu/esp*: add RTT_MIN_OFFSET definition (#22869)
cpu/GBA: Add module stdio_mgba for stdout via debug regs of mGBA
emulator (#22760)
cpu/GBA: Add timer peripheral (#22776)
cpu/riscv_common: add rv64 support (#22547)
cpu/efm32: add coretemp for series 2 (#22611)
cpu/efm32: add ethernet driver (#22306)

cpu/efm32: provide RTT_MIN_OFFSET (#22874)
cpu/efm32: remove unsupported where now supported (#22666)
cpu/lpc23xx: clean up some doc and code (#22917)
cpu/native: check if uart is within bounds (#22668)

cpu/noelv: add support for Gaisler NOEL-V on ZedBoard (#22548)
cpu/nrf9160: prepare for TrustZone-M non-secure builds (#22728)

cpu/riscv/periph/xh3irq: hide print behind debug (#22557)
cpu/riscv_common/irq_arch: fix wrong print kconfig check (#22558)
cpu/riscv_common: move trap print to specific debug define (#22362)

cpu/stm32: add initial STM32U3 and nucleo-u385rg-q support (#22427)

cpu/stm32: cleanup cpu_conf.h (#22792)
Fix gba timer, Update timer test, cleanup ARM7common (#22908)
makefiles: get rid of arch_efm32 (#22651)

Device Drivers

drivers/lm75: mixed bag of small fixes (#22532)

drivers/max31343: add driver for MAX31343 I2C RTC (#22115)
drivers/max313xx: rename max31343 to max313xx, add support for
MAX31331 (#22546)
drivers/qma6100p: add QST QMA6100P 3-axis accelerometer driver (#22352)

Documentation

boards/stm32c0116dk: add to doc page MCU table (#22642)
boards/stm32g0316-disco: add MCU table to doc page (#22590)
doc/guides: add guide for porting new MCUs (#22173)
doc/guides: add page on continuous integration (takeover of #18721) (#22434)
doc/guides: migrate rpl networking guide from wiki (#22460)

doc/guides/ai_policy: Make human communication mandatory (#22433)

doc/starlight: Cleanup doxygen and add doxygen image endpoint (#22662)

boards/stm32f0discovery: update doc page (#22608)
CONTRIBUTING: update documentation section (#22483)

CONTRIBUTING.md: add section about extractive contributions (#22706)

doc/GOVERNANCE.md: update Weekly Meeting text (#22199)
doc/guides/finding_modules: make inclusion clearer (#22485)
doc/guides: improve patching section in Package Port guide (#22739)
doc/guides: Port unicoap guides (#22482)
doc/guides: Revamp index site (#22520)
doc/starlight: split sidebar into categories (#22481)
doc/starlight: Update and migrate to new rust md parser (#22661)
doc: move static images to doc/resources (#22436)
drivers/shield_w5100: document interrupt solder jumper (#22741)

LICENSES: Add BSD-1-Clause, BSD-2-Clause, CC0-1.0, ICU (#22475)

guides: move IoT-LAB build-system integration docs to guides (#22928)
treewide: format Python docstrings per PEP 257 (#22806)

SECURITY.md: prefer Github SA, add checklist (#22907)

pkg/[a-n]*: move licenses from headers to SPDX format (#22742)
pkg/[o-y]*: move licenses from headers to SPDX format (#22796)
pkg: make license declarations spdx compatible (#21650)
sys/[i-n]*: replace license headers with SPDX (#22612)
sys/include: use SPDX license tags [n] (#22477)

sys: add missing SPDX (#22922)

sys/[a-h]*: replaced license headers with SPDX format (#22323)
sys/include: use SPDX license tags [a-m] (#22476)
sys/include: use SPDX license tags [o-z] (#22478)
{examples,sys}/psa_crypto: remove notes aboute Kconfig (#22843)

Build System / Tooling

.clang-format: update based on feedback (#22833)

.murdock: always add changed boards to quickbuild (#22787)

dist: remove unused gdbinit-docker script (#22722)

dist/tools/compile_commands: add -Wdocumentation for --clangd (#22450)
dist/tools/print_toolchain_versions: add docker & podman (#22523)

dist/license/check: prefer spdx (#22596)

licences/check.sh: add capability to exclude files from check (#22913)
Makefile.include: add $(APPDIR)/include to the INCLUDES search
paths (#22713)
Review Process: Get Formatter to align with coding conventions (#22679)

build system: migrate to echoinfo, echogreen, ... for warnings
and info printed to stderr (#22521)
build-system: use relative paths in debug symbols (#22826)
buildsystem: avoid using .NOTPARALLEL (#22898)
ci: use github annotations for guide check (#22686)
CODING_CONVENTIONS: use Python 3.14 (#22974)
dist/licenses: exclude more autogenerated files (#22920)
dist/tools/compile_test: skip unsupported toolchain & insufficient
memory boards (#22653)
dist/tools/toolchains: remove outdated scripts (#22627)
doccheck: less exclude_simple (#22513)
Makefile.include: compute RIOT_VERSION_CODE without $(shell) (#22780)
makefiles/arch/cortexm: drop Ubuntu bionic GCC check (#22712)
makefiles/docker.inc.mk: bump docker image version after flake8
update and clang-format addition (#22694)
makefiles/docker.inc.mk: bump docker image version after update to
Resolute Raccoon 🦝 (#22692)
makefiles/docker.inc.mk: bump riotdocker image hash after Picolibc
and other fixes (#22838)
makefiles/docker.inc.mk: bump riotdocker version after LLVM 20 update (#22809)
makefiles/docker: bump Docker image version after C2Rust update (#22635)
makefiles/docker: bump Docker image version after LLVM update (#22645)
makefiles/docker: bump Docker image version after Python updates (#22629)
makefiles/docker: update riotbuild digest (#22697)
makefiles/info-global: speedup info-boards-* targets by using
parallel execution (#22355)
static-test/clang-format: improve message localisation (#22791)
treewide: fix flake8 errors (#22695)
treewide: reduce usage of shell in Makefiles (#22669)
uncrustify: do not align on tabstops (#22849)

Examples

examples/advanced/xipfs: Add mountpoint memory image inclusion and
mi… (#22345)
examples/micropython: add some slack to timeout (#22953)
examples/micropython: add some slack to timeout [backport 2026.10] (#22963)

examples/rust-gcoap: enable compilation for native again (#22688)

Testing

.github: check that PR description contains AI declaration (#22474)
tests/build_system/riot_version: add test (#22779)
tests/build_system: add test for relative paths (#22667)
tests/cpu/efm32_info: add test application (#22643)
tests: add missing RIOT-branding SPDX identifier (#22923)

.murdock: remove -gz from CFLAGS BLACKLIST (#22681)
.murdock: skip unnecessary make clean (#22672)
test-on-iotlab.yaml: bump Python to 3.14 (#22954)
tests/[b-n]*: move licenses to SPDX format (#22842)
tests/[p-u]*: move licenses to SPDX format (#22872)
tests/periph/rtt_min: fail if RTT_MIN_OFFSET is not high enough (#22618)
tests/unittests: drop use of deprecated nanocoap APIs (#22860)
tests/timer: Ensure timer remain stopped when setting (#22789)
tests: fix static tests warnings (#22652)

API Changes

drivers/periph/dac: add dac_play API for async multi sample output (#22261)

net/ieee802154: Drop NETOPT_CHANNEL_PAGE (#22740)
sys/cpp11-compat: deprecate the C++11 threading header (#22906)

And 102 minor changes.

Deprecations

Deprecations (7)

boards/{im880b,lobaro-lorabox}: add deprecation warning for 2027.04 (#22715)
drivers/cc2420,boards/{telosb,z1}: add deprecation warning for
2027.04 (#22716)
makefiles/tools/stm32loader: add deprecation warning (#22714)
pkg/edhoc-c: add deprecation notice (#22803)
sys/stdio: add stdio_notify to emit callback on write (#22429)

boards/stm32f030f4-demo: deprecate board (#22264)
pkg/pkg.mk: Use git apply for CI runs, deprecate GITAMFLAGS (#22851)

Removals (8)

core/thread.h: remove deprecated THREAD_CREATE_STACKTEST (#22854)
dist/tools: remove vagrant (#22711)
dist/tools: remove desvirt (#22724)
gnrc/ipv6/nib: remove deprecated STATIC_LLADDR_IS_FIXED (#22856)
makefiles: evaluate RIOT_VERSION_GIT lazily (#22733)
pkg/bplib: remove unordered storage (#22814)
sys/net/nanocoap: drop deprecated APIs (#22867)
treewide: remove deprecated BOARDSDIR variable (#22723)

Bug fixes (119)

boards/rpi-pico,cpu/rpx0xx: add default I2C configuration, fix I2C
sanity checks and I2C state machine (#22844)
cpu/esp_common/esp-wifi: add esp-now include path if esp_now is used (#22987)
makefiles/docker: conditionally add BINDIR as docker volume (#22631)
net/unicoap/server: Add missing unicoap_response_status_from_errno (#22588)
pkg/mpaland-printf: add targets for newlib's internal iprint
endpoints (#22935)
pkg/wakaama: add missing break statements (#22878)
tests/ieee802154: add missing boards (#22720)
boards/nucleo: Select lpuart when using stdio_slipdev (#22605)
boards/same54-xpro: fix candev parameter order (#22804)
boards/zedboard-noelv: fix defgroup, which allows correct link
genera… (#22746)
boards: update documentation for EFM32 boards (#22637)
cpu/efm32: improve PWM driver (#22665)
cpu/efm32: prevent spurious timer interrupt (#22703)
cpu/esp/esp-wifi: fix LINK_UP for SoftAP interface (#22930)
cpu/esp32/stdio_usb_serial_jtag: don't drop output if TX buffer is
full (#22929)
cpu/esp32: fix release of recursive lock (#22829)
cpu/esp8266/vendor: wait for flash cache to be enabled (#22864)
cpu/esp_common/esp_now: fix flakiness and various small fixes (#22919)
cpu/esp_common: erase block/sector-wise to leave interrupt time (#22945)
cpu/gba: Make stdio_{fb, mgba} available to the stdio dispatcher (#22889)
cpu/native/mtd_native: correct bound checks (#22646)
cpu/nrf52/radio/nrf802154: fix cca send (#22900)
cpu/nrf52/radio/nrf802154: remove ifs (#22904)
cpu/nrf5xcommon/periph/qdec: fix LED initialization and sample period (#22700)
cpu/riscv_common: temporarily disable rust support (#22687)
cpu/rpx0xx: build .pio.h header files out of tree (#22773)
cpu/samd5x,samd21: define RTT_MIN_OFFSET (#22600)
cpu/stm32: fix RTC&RTT init on LSI/LSE switch (#22848)
cpu/stm32: move vendor header pkg script to pkg/stm32cmsis (#22786)
cpu/{rp2350_common, rpx0xx}: fix uart_poweron and uart_poweroff (#22802)
cpu: fix stm32l1 crash on wakeup (#22863)
dist/tools/clang_format: fix escape characters (#22897)
dist/tools/vera++: remove deleted profile from profile list (#22709)
dist/tools: fix regressions from #22597 (#22598)
dist/tools: fix running with ZSH, minor fixes (#22817)
dist/tools: fix some shellcheck errors and warnings (#22597)
doc/boards: fix pinout path for Nucleo and other Stm32 boards (#22506)
doc/starlight: fix pinout for nucleo-c031 (#22559)
drivers/at86rf215: prevent driver from stalling (#22805)
drivers/greth: fix RX stalls and 32-bit build (#22766)
drivers/mtd_emulated: fix _write_page (#22659)
drivers/mtd_flashpage: fix buffer overflow (#22940)
drivers/sx126x: fix ISR handling (#22868)
drivers/sx127x,pkg/semtech-loramac: fix initialization of driver (#22926)
drivers/{kw2xrf,mrf24j40,xbee}: don't modify short address (#22950)
drivers: check result of I2C reads during initialization (#22891)
esp-ieee802154: fix RSSI and LQI values reported after RX (#22682)
gnrc/ipv6_auto_subnets: prevent overflow if prefix_len is too large (#22839)
gnrc_ipv6: handle netif == NULL on source address validation (#22924)
gnrc_sixlowpan_iphc: increase test coverage and several bug fixes (#22727)
Makefile.include: fix .NOTPARALLEL for make v4.4 (#22890)
makefiles/docker.inc.mk: bump riotdocker version after murdock- worker update (#22813)
makefiles/info-global: fix info-buildsizes-diff (#22885)
makefiles/setup_dirs.inc.mk: split out and improve dir setup (#18530)
makefiles/toolchain/afl: make compatible with current riotdocker (#23014)
makefiles/tools/esptools, cpu/esp32: fix esptool build (#22825)
makefiles: filter stdio_default with STDIO_MODULES (#22424)
net/ieee802154/submac: deactivate cca send before an ack transmission (#23008)
net/unicoap/doc: fix typos and links (#22670)
net/unicoap/message.h: set payload_representation in message_init_* (#22544)
net/unicoap: fix removal of multiple trailing options (#22515)
net/unicoap: several dependency fixes (#22883)
pkg, boards & examples: fix static tests warnings (#22671)
pkg/jerryscript: disable warning for LLVM 20 (#22790)
pkg/libcoap: simplify Makefile, enable BUILD_DIR (#23004)
pkg/lwip: increase stacksize for tcpip thread (#22941)
pkg/lwip: round sub-millisecond timeouts up to 1 ms (#22644)
pkg/pkg.mk: fix warnings about PKG_SOURCE_LOCAL (#22781)
pkg/tinyusb/cdc_acm_stdio: fix deadlock on startup (#22925)
posix/sockets: Prevent potentially long wait with multiple posix TCP
sockets (#21784)
stm32/candev: change candev_stm32_isr flags to uint8_t (#22650)
sys/crypto/ocb: use use of secure helpers: (#22797)
sys/event: fix thread safety issue (#22648)
sys/nanocoap: fix handling blockwise transfer (#22518)
sys/net/dhcpv6: reject truncated option headers (#23018)
sys/net/gnrc/rpl: reject zero MinHopRankIncrease in DIO (#23019)
sys/net/gnrc/tcp: clear receive buffer on listening (#22749)
sys/net/gnrc/tcp: unschedule connection timer on listening (#22748)
sys/net/gnrc_sixlowpan_frag: fix OOB read (#22798)
sys/net/ipv4: fix internet header length (#22552)
sys/net/link_layer/ieee802154/submac.c: fix negative integer
evaluation to bool (#22952)
sys/net/link_layer/ieee802154/submac.c: fix negative integer
sys/net/nanocoap: abort link format listing on too small buffer (#22879)
sys/net/nanocoap_fileserver: always check return value of
_resp_init() (#22745)
sys/net: fix unicoap dtls (#22581)
sys/random/fortuna: bug fixes and improvements (#22388)
sys/rtc_utils: correctly handle units rolling under (#22357)
sys/suit: release worker lock on invalid URL in suit_worker_trigger() (#22896)
sys/uri_parser: reject IPv6 host without closing bracket (#22895)
sys/walltime/shell: fix NUL char in terminal (#22834)
sys: make auto init default with DHCPv6 client (#21178)
test-on-iotlab: use correct radio for nucleo-wl55jc (#22956)
testbed-support: iotlab: fix nucleo-wl55jc radio (#22960)
testrunner / tests: flush pexpect spawn before test run, expose
functionality (#22942)
tests/sys/ssp: fix IoT-Lab hang for samr38-xpro (#22958)
tests/unicoap: correct order of exp and act in TEST_ASSERT_* (#22595)
tests/unittests: prevent ASAN false positive with native32 (#22823)
tests: fix synchronization issues where necessary (#22951)
treewide: fix copy-paste related mistakes (#22800)
treewide: fix GCC string termination warnings (#22881)
treewide: fix missing $(shell) in commands (#22765)
treewide: fix shellcheck errors to pass static-tests again (#22654)
treewide: name truncation fixes for filesystems (#22876)
{doc,examples}/guides: fix incorrect board name (#22788)
{pkg,makefiles,dist/tools,cpu/rpx0xx}: move pioasm to picosdk (#22657)

Known issues

Network related issues (55)

6lo: RIOT does not receive packets from Linux when short_addr is set (#11033)
Address registration handling inappropriate (#15867)
app/netdev: application stops working after receiving frames with
assertion or completely without error (#8271)
at86rf2xx: Dead lock when sending while receiving (#8242)
cord_lc: RD lookup overflow branch sets a flag but doesn't return, so
the response is memcpy'd past the caller's buffer (#22961)
cpu/esp8266: Tracking open problems of esp_wifi netdev driver (#10861)
DHCPv6 client: Handling of NotOnLink incorrect (#20349)
dist/tools/sliptty/start_network.sh: IPv6 connectivity is broken on
PC (#14689)
driver/mrf24j40: blocks shell input with auto_init_gnrc_netif (#12943)
drivers/at86rf215: Incorrect channel number set for subGHz (#15906)
DTLS examples cannot send message to localhost (#14315)
Emcute cannot create a double-byte name (#12642)
ethernet: Missing multicast addr assignment (#13493)
ethos: fails to respond to first message. (#11988)
ethos: Unable to handle fragmented IPv6 packets from Linux kernel (#12264)
example/gnrc_border_router cannot answer after some time (#19578)
examples/cord_ep: Dead lock when (re-)registering in callback
function (#12884)
examples/gnrc_border_router: esp_wifi crashes on disconnect (#14679)
Forwarding a packet back to its link layer source should not be
allowed (#5051)
gcoap DNS (DoC): Block2 offset overflows the bounds check and writes
OOB on 32-bit targets (#22985)
gcoap example request on tap I/F fails with NIB issue (#8199)
gcoap: Suspected crosstalk between requests (possible NULL call) (#14390)
Global IPv6 addresses remain deprecated after receiving RA (#19846)
gnrc ipv6: multicast packets are not dispatched to the upper layers (#5230)
gnrc/ipv6: "invalid payload length" - corrupted IPv6 header when
ENABLE_DEBUG=1 in mbox.c (#20390)
gnrc_border_router stops routing after a while (#16398)
gnrc_border_router: Kconfig and C disagree about number of addresses
per interface (#19947)
gnrc_icmpv6_echo: flood-pinging another node leads to leaks in own
packet buffer (#12565)
gnrc_ipv6: Multicast is not forwarded if routing node listens to the
address (#4527)
gnrc_netif_pktq leaks memory (#17924)
gnrc_rpl: missing bounds checks in _parse_options (#16085)
gnrc_rpl: nib route not updated when topology / DODAG changes (#17327)
gnrc_rpl: takes unusually long time to start routing packets (#19147)
gnrc_sock_udp: Possible Race condition on copy in application buffer (#10389)
gnrc_tcp: gnrc_tcp_recv() never generates -ECONNABORTED (#17896)
ieee802154/kw2x: radio gets stuck (#22614)
ieee802154_submac: IPv6 fragmentation broken (#16998)
LoRaWan node ISR stack overflowed (#14962)
lwip_sock_tcp / sock_async: received events before calling
sock_accept() are lost due to race condition. (#16303)
Missing drop implementations in netdev_driver_t::recv (#10410)
Neighbor Discovery not working after router reboot when using SLAAC (#11038)
nrf52: Not able to add global or ULA address to interface (#13280)
nrfmin: communication not possible after multicast ping with no
interval (#11405)
ping6 is failing when testing with cc2538dk (#13997)
pkg/lwip: race condition (data loss) in async connection setup (#21874)
pkg/tinydtls: auxiliary data API does not work for async sockets (#16054)
Removing a TNT global address then adding a new one does not work (#20318)
samr30 xpro doesn't seem to use its radio ok (#12761)
stale border router does not get replaced (#12210)
sys/net/gnrc: Surprise stack overflow by user code in GNRC when
gnrc_netapi_callbacks is enabled (#22649)
TCP client cannot send read only data (#16541)
test/lwip: enabling both, IPv4 and IPv6, results in unexpected
behavior (#18097)
tests/lwip: does not compile for IPv4 on 6LoWPAN-based boards. (#17162)
two nodes livelock sending neighbor solicitations back and forth
between each other (#16670)
xbee: setting PAN ID sometimes fails (#10338)

Timer related issues (6)

Bug: timer setup can expose new callback or temporary timer state to
IRQ handlers before setup finishes (#22410)
misc issues with tests/trickle (#9052)
periph/timer: timer_set() underflow safety check (tracking issue) (#13072)
periph_timer: systematic proportional error in timer_set (#10545)
saml21 system time vs rtc (#10523)
sys/newlib: gettimeofday() returns time since boot, not current wall
time. (#9187)

Drivers related issues (10)

at86rf2xx: Simultaneous use of different transceiver types is not
supported (#4876)
cpu/msp430: GPIO driver doesn't work properly (#9419)
drivers/at86rf215: The activation of the address match interrupt is
missing in the at86rf215_reset function (#20505)
examples/dtls-wolfssl not working on pba-d-01-kw2x (#13527)
fail to send data to can bus (#12371)
periph/spi: Switching between CPOL=0,1 problems on Kinetis with
software CS (#6567)
periph: GPIO drivers are not thread safe (#4866)
PWM: Single-phase initialization creates flicker (#15121)
STM32: SPI clock not returning to idle state and generating
additional clock cycles (#11104)
tests/periph_flashpage: unexpected behavior on nucleo-l4r5zi (#17599)

Native related issues (4)

native not float safe (#495)
native: tlsf: early malloc will lead to a crash (#5796)
sys/vfs: VFS_READ show correct data on every SECOND request only (#21470)
ztimer doesn't wake up on native if the pm_layered module is used (#21083)

Other platforms related issues (11)

Failing tests on FE310 (Hifive1b) (#13086)
boards/hifive1: flashing issue (#13104)
cpu/sam0: flashpage write / read cycle produces different results
depending on code layout in flash (#14929)
gcoap/esp8266: Stack overflow with gcoap example (#13606)
Get serial to work on ESP32-S3 chipset (#22527)
Interrupt callback function is instantly called on samd51 after
setting it from within interrupt callback function (#19861)
MPU doesn't work on cortex-m0+ (#14822)
newlib-nano: Printf formatting does not work properly for some
numeric types (#1891)
periph_timer: Test coverage & broken on STM32F767ZI (#15072)
riscv: ISR stack is too small for ENABLE_DEBUG in core files (#16395)
stm32f7: Large performance difference between stm32f746 and stm32f767 (#14728)

Build system related issues (7)

Build dependencies - processing order issues (#9913)
build system: dependency files not updated when relevant environment
variables change (e.g. BUILD_DIR) (#22531)
dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck
1.89 (#12771)
Kconfig: Unable to set Kconfig boolean variables with default true to
false (#21785)
make: ccache leads to differing binaries (#14264)
make: use of immediate value of variables before they have their
final value (#8913)
makefiles: make term does not print stderr output of child
process. (#21808)

Other issues (84)

[nRF5x] periph_uart unreliable with GCC 9.3.1 (#21842)
[tracking] Bugs found by the peripheral selftest (#20071)
[Tracking] Failures found with testing on real hardware for release (#21882)
[Tracking] Fix failures of test-on-iotlab (#20791)
[TRACKING] sys/shell refactoring. (#12105)
[tracking] unnecessary use of floating point arithmetic (#19614)
_NVIC_SystemReset stuck in infinite loop when calling pm_reboot
through shell after flashing with J-Link (#13044)
make term no longer works with JLinkExe v6.94 (#16022)
at86rf215 stops receiving until sending a packet (#19653)
backport_pr: Only works for when fork is in user (not in
organization) (#18486)
benchmark_udp: hammering with low interval causes issues (#16808)
Bug: adafruit-feather-nrf52840-sense is not reachable over USB after
flashing with UF2_SOFTDEV=SD611 (#22448)
Bug: RTT/WDT callback setup can let overflow or early-warning IRQs
use new callback state before setup finishes (#22411)
Bug: same-UART re-initialization can let a pending UART IRQ use the
new callback before setup finishes (#22408)
Bug: UART reconfiguration can expose temporary callback or data-mask
state to RX IRQ handlers (#22409)
Builds fail when different execstack options are around in objects (#18522)
Can't build relic with benchmarks or tests (#12897)
CC2538-CC2592EM has a very weak transmit power (#17543)
ci/clang-format: Master merge CI runs are completely unreadable (#22827)
clang-format, uncrustify: clang-format and uncrustify are fighting (#22811)
cpp: Exception handling undefined (#17523)
cpu/stm32: fix STM32G4 flash writes failing after motor driver init (#22151)
cpu/stm32: some tests are failing on CM33 (l5, u5) (#17439)
cpu/stm32: watchdog initialization for STM32L4 broken (#22801)
doc/boards: information concerning access to RIOT shell (#17453)
doc/doxygen: reduce excluded errors (#22327)
doxygen: CSS hack to hide doc breaks on older browsers (#21312)
drivers/dose: ctx->state is loaded and stored outside state() (#22754)
drivers/slipdev: dev->state checked twice, and stored, while the RX
callback is live (#22755)
edbg: long lines flooded over serial become garbled (#14548)
examples / tests: LoRa tests fail on platforms that don't support
LoRa (#14520)
examples/gcoap: client broken (#19379)
flashing issue on frdm-k64f (#15903)
frdm-k22f failing tests/periph_flashpage (#17057)
frdm-k22f fails tests/periph_timer (#19543)
Freeze into semtech_loramac_send call (pkg/semtech-loramac) (#18790)
gcoap: gcoap_req_send and related should return negative for errors (#19393)
gnrc_ipv6_nib: Neighbor Solicitation ping-pong (#18164)
ieee802154_security: Nonce is reused after reboot (#16844)
kconfiglib.py choice override of menuconfig bug (#19069)
LVGL tests produce unaligned code, fail to build (#20110)
lwip: drivers/at86rf2xx/at86rf2xx_netdev.c invalid state during TCP
disconnect (#17209)
lwip: invalid state transition on ieee802154_submac users (#17208)
Making the newlib thread-safe (#4488)
mcuboot: flashes but no output (#17524)
MTD is confusing (#17663)
openDSME example application does not work reliable out of the box
with nRF52840 MDK Dongles (#21922)
Order of auto_init functions (#13541)
periph_rtt: rtt_set_alarm() blocks IRQ for 80 plus usec on STM32 (#19520)
pkg/tinydtls: Multiple issues (#16108)
Potential race condition in compile_and_test_for_board.py (#12621)
RIOT is saw-toothing in energy consumption (even when idling) (#5009)
riotboot: ECC faults (eg. in STM32L5 or STM32WB) not handled
gracefully (#17874)
rust-gcoap example is incompatible with littlefs2 (#17817)
Samr30/gpio: Erasing then write mux can generate spurious IRQ (#19993)
samr34-xpro: some tests failing (#19223)
sock_dtls: unable to send big messages (#17996)
spurious IRQs in periph_timer (#18976)
Starlight: "Supported Boards" and "Supported CPUs" Known Issues (#22203)
stdio UART input truncated (#21564)
stdio_ethos: infinite shell loop (#17972)
STM32 Nucleo boards improperly clocked (#19778)
STM32F4-discovery + mrf24j40 not working (#19711)
sys/riotboot: documentation issues (#11243)
sys/usb/usbus/cdc/ecm: interface thread blocked when connected host
interface is down (#21098)
tests/lwip target board for python test is hardcoded to native (#6533)
tests/periph_flashpage: failing on stm32l475ve (#17280)
tests/pkg/relic is failing on samr21-xpro when built using llvm (#19903)
tests/pkg_libhydrogen: test fails on master for the samr21-xpro with
LLVM (#15066)
tests/pkg_libschc: Failing test_reassemble_success_ack_always (#19445)
tests/riotboot does not pass on iotlab-m3 (#22006)
tests/test_tools: test fails while testing on samr21-xpro/iotlab-m3 (#15888)
tests: broken with stdio_rtt if auto_init is disabled (#13120)
tests: some tests don't work with newlib lock functions. (#12732)
Tracking: callback state can become visible before pending IRQ state
is cleared in several RIOT peripheral drivers (#22405)
tracking: failing tests with stdio_cdc_acm (#21231)
tracking: fixing warnings in RIOT static test (#22216)
Types in byteorder.h need a cleanup (#14737)
USB identifiers with funny characters create mojibake (#17776)
usbus/msc: wrong error handling and behavior after usb reset (#19478)
usbus: endpoint number from the SETUP packet indexes the endpoint
arrays with no bounds check (#22986)
Use of multiple CAN bus on compatible boards (#14801)
ztimer is incompatible with real-time requirements (#18883)
ztimer_periodic: occasional lockups (#21374)

There are 177 known issues in this release

Fixed Issues since the last release (2026.07)

cpu/nrf52/radio/nrf802154: ACKs are not sent reliably (CCA done for
ACKs?) (#23005)
lwip,gnrc,nrf802154: UDP packet sent from LWIP is not received on
GNRC (#22943)
lwip, submac: DoS at received UDP packet (#22938)
clang-format: Control Characters not escaped in github annotations (#22888)
libasan reports OOB error for timer_settime() on native32 (#22822)
Clang Format: Proposed patch should be pinned at important line (#22759)
cpu/nrf52: crash when using periph_uart_nonblocking (#22751)
pkg/picosdk: generated header files not cleaned (#22673)
treewide: Warnings generated by Coccinelle (#22625)
2026.07 Release specs failures (#22603)
Bug: same-pin GPIO interrupt reconfiguration can let a pending IRQ
use the new callback before setup finishes (#22407)
Bug: same-instance qdec_init() can let a pending QDEC IRQ use the new
callback before setup finishes (#22406)
boards/nucleo-f767zi: Switching clock sources causes the system to
hang until power on reset (#22376)
Board pinout diagram 404 on the guides site (#22353)
sys/psa_crypto/doc.md: needs rework after most of Kconfig was removed (#22329)
lwip, submac: deadlock on user transmission (#21843)
drivers/at86rf215: not returning RX/IDLE after a while of operation
with RPL/UDP (#21685)
I2C Crashes Kernel on Raspberry Pi Pico (#21187)
pkg/semtech-loramac: _lock_acquire called in interrupt context causes
kernel panic on esp32-ttgo-t-beam and possibly other esp boards (#20799)
core/lib: print_stack_usage_metric called with misaligned stack (#20492)
toolchain: C2Rust fails on native on Arch (#20451)
LWIP TCP Communication Error (#19676)
stdio_tinyusb_cdc_acm hangs with picolibc (#19277)
EXTERNAL_MODULE_DIRS silently ignores non-existent entries (#17696)
boards/esp32-wroom-32: tests/mtd_raw flakey (#16130)
examples/micropython: floating point exception while testing on
native (#15870)
mdt_erase success, but vfs_format resets board (esp32-heltec-
lora32-v2) (#14506)
esp32-wroom-32: tests/netstats_l2 failing sometimes (#14237)
netdev_ieee802154: Mismatch between radio ll address and in memory
address (#10380)

29 fixed issues since last release (2026.07)

Acknowledgements

We would like to thank all companies that provided us with hardware for porting
and testing RIOT. Further thanks go to companies and institutions that
directly sponsored development time. And finally, big thanks to all of you
contributing in so many different ways to make RIOT worthwhile!

More information

http://www.riot-os.org

Discussions

Join the RIOT Matrix room at: #riot-os:matrix.org
Join the RIOT Forum at: forum.riot-os.org
Follow us on Mastodon: floss.social/@RIOT_OS

License

The code developed by the RIOT community is licensed under the GNU Lesser
General Public License (LGPL) version 2.1 as published by the Free Software
Foundation.
Some external sources and packages are published under a separate license.

All code files contain licensing information.

Release-2026.10