Jackson Release 2.21.6

Patch version of 2.21, under development as of July 2026.

Following fixes will be included in this patch release.

Changes, core

Streaming

#6099: Resolve classes without initialization in TypeFactory.findClass()

Databind

• #6101: @JsonInclude(NON_EMPTY, content=CUSTOM) does not omit a Map property after all entries are filtered

Changes, dataformats

Protobuf

• #708: Proto3 fields without label fail to parse
• #714: Packed repeated field fails to decode when array spans an input buffer reload
• #715: ProtobufGenerator._reportWrongWireType() always reports string, ignoring actual type

Smile

• #720: SmileGenerator writes past output buffer (ArrayIndexOutOfBoundsException) for very long Strings due to int overflow in maxLen

TOML

• #702: Expand TOML dotted key nesting checks