Bump twisted from 25.5.0 to 26.4.0rc2

[dependabot]

Bumps twisted from 25.5.0 to 26.4.0rc2.

Release notes

Sourced from twisted's releases.

Twisted 26.4.0rc2 (2026-04-29)

This is the last release with support for Python 3.9.

Security

• twisted.names was fix for Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. Reported and fixed by Tomas Illuminati Balbin CVE-2026-42304 (#12626)

Features

• twisted.internet.ssl.CertificateOptions has a new constructor argument, contextForServerName, which takes a callback that will get invoked when a client sends a server name indication, with the sent servername, and returns a new OpenSSL.SSL.Context that the connection will switch to. (#4887)
• twisted.internet.endpoints.serverFromString now supports the tls endpoint type, which allows you to do twist web --listen=tls:.../certbot-dir/config/live pointed at a certbot live configuration directory and have your certbot certificates automatically discovered and served appropriately. (#9885)
• twisted.internet.reactor now has type annotations and will appear to be an object of an appropriate type, allowing for idiomatic common usages with correct type information. (#9909)
• twisted.conch.ssh.SSHUserAuthServer now supports the security key ssh types "sk-ecdsa-sha2-nistp256@openssh.com" and "sk-ssh-ed25519@openssh.com" and extracting the application property from these new key types. (#12212)

Bugfixes

• twisted.internet.mail will now return a meaningful Failure when TLS validation fails. (#10210)
• TLS version range constraints passed to twisted.internet.ssl.CertificateOptions are now properly respected rather than excluding the version being passed as the desired constraint. (#10232)
• A potential reference cycle that might cause intermittent memory spikes while using twisted.internet.defer.inlineCallbacks was removed. (#12120)
• Trial no longer emits the error RuntimeWarning: TestResult has no addDuration method when running PyUnit tests. (#12229)
• twisted.python.rebuild.rebuild() now handles changes to sys.modules gracefully. Prior to the change, it could possibly raise a "dictionary changed size during iteration" error if the module list changed. (#12458)
• twisted.internet.protocol.ReconnectingClientFactory: Don't multiply by factor for initial delay, but use initialDelay directly. (#12478)
• twisted.internet.ssl and twisted.protocols.tls no longer mutate the pyOpenSSL context after creating pyOpenSSL connections, maintaining compatibility with an upcoming version of pyOpenSSL and increasing reliability (possibly even fixing a very rare segfault) (#12500)
• twisted.internet.testing.MemoryReactor.callWhenRunning now invokes the callback immediately, if already started. (#12514)
• Twisted now correctly detects EOF on OpenSSL 4. (#12632)

Improved Documentation

• The example code from the documentation describing how to create a custom DNS server was updated to Python3. (#12480)
• Type annotations now use modern PEP 585 built-in generics and PEP 604 union syntax throughout the project. (#12556)

Deprecations and Removals

... (truncated)

Changelog

Sourced from twisted's changelog.

This file contains the release notes for Twisted.

It only contains high-level changes that are of interest to Twisted library users. Users of Twisted should check the notes before planning an upgrade.

Ticket numbers in this file can be looked up by visiting https://twisted.org/trac/ticket/

.. towncrier release notes start

Twisted 26.4.0 (2026-05-11)

This is the last release with support for Python 3.9. No changes since 26.4.0rc2.

Security

• twisted.names was fix for Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. Reported and fixed by Tomas Illuminati Balbin CVE-2026-42304 (#12626)

Features

• twisted.internet.ssl.CertificateOptions has a new constructor argument, contextForServerName, which takes a callback that will get invoked when a client sends a server name indication, with the sent servername, and returns a new OpenSSL.SSL.Context that the connection will switch to. (#4887)
• twisted.internet.endpoints.serverFromString now supports the tls endpoint type, which allows you to do twist web --listen=tls:.../certbot-dir/config/live pointed at a certbot live configuration directory and have your certbot certificates automatically discovered and served appropriately. (#9885)
• twisted.internet.reactor now has type annotations and will appear to be an object of an appropriate type, allowing for idiomatic common usages with correct type information. (#9909)
• twisted.conch.ssh.SSHUserAuthServer now supports the security key ssh types "sk-ecdsa-sha2-nistp256@openssh.com" and "sk-ssh-ed25519@openssh.com" and extracting the application property from these new key types. (#12212)

Bugfixes

• twisted.mail.smtp will now return a meaningful Failure when TLS validation fails. (#10210)
• TLS version range constraints passed to twisted.internet.ssl.CertificateOptions are now properly respected rather than excluding the version being passed as the desired constraint. (#10232)
• A potential reference cycle that might cause intermittent memory spikes while using twisted.internet.defer.inlineCallbacks was removed. (#12120)
• Trial no longer emits the error RuntimeWarning: TestResult has no addDuration method when running PyUnit tests. (#12229)
• twisted.python.rebuild.rebuild() now handles changes to sys.modules gracefully. Prior to the change, it could possibly raise a "dictionary changed size during iteration" error if the module list changed. (#12458)
• twisted.internet.protocol.ReconnectingClientFactory: Don't multiply by factor for initial delay, but use initialDelay directly. (#12478)
• twisted.internet.ssl and twisted.protocols.tls no longer mutate the pyOpenSSL context after creating pyOpenSSL connections, maintaining compatibility with an upcoming version of pyOpenSSL and increasing reliability (possibly even fixing a very rare segfault) (#12500)
• twisted.internet.testing.MemoryReactor.callWhenRunning now invokes the callback immediately, if already started. (#12514)
• Twisted now correctly detects EOF on OpenSSL 4. (#12632)

... (truncated)

Commits

• b69a0c7 Update version.
• b32c661 Fix tag check.
• 819185e Fix mypy.
• 290cbf5 [pre-commit.ci] auto fixes from pre-commit.com hooks
• cb9783c Manual updates for release notes.
• ac504cc Prepare the rellease.
• 2d19612 Merge commit from fork
• 44c11c7 Merge branch 'trunk' into advisory-fix-1
• 9ca319e Update src/twisted/names/newsfragments/12626.bugfix
• 46f0e5c #12566 Revert the removal of assertEquals and assertNotEquals. (#12628)
• Additional commits viewable in compare view

Note
Automatic rebases have been disabled on this pull request as it has been open for over 30 days.

[alexreinking]

@dependabot rebase

[dependabot]

OK, I won't notify you again about this release, but will get in touch when a new version is available. If you'd rather skip all updates until the next major or minor version, let me know by commenting @dependabot ignore this major version or @dependabot ignore this minor version.

If you change your mind, just re-open this PR and I'll resolve any conflicts on it.