Jackson Release 2.21.1

Patch version of 2.21, released on February 22, 2026.

Following fixes are included in this patch release.

Changes, core

Streaming

• #1548: StreamReadConstraints.maxDocumentLength not checked when creating parser with fixed buffer
• #1555: Enforce StreamReadConstraints.maxNumberLength for non-blocking (async) parser

Databind

• #5184: @JsonIgnore on record method applied to record matching field at deserialization
  • Also fixed duplicate issue #5624
• #5616: ObjectWriter serializes reference types (like AtomicReference, Optional) with subtypes incompletely
• #5674: Fix NPE when deserializing Throwable with null "stackTrace"
• #5706: TokenBuffer serialization fails when buffer contains integer encoded as String

Changes, data formats

Avro

• #645: Remove use of Avro Schema.Parser().setValidate() to allow use of Avro core 1.12.1 (2.x)

CBOR

• #649: StreamReadConstraints.maxDocumentLength not checked when creating parser with fixed buffer
• #652: Ensure CBOR backend supports StreamReadConstraints.maxTokenCount

Smile

• #649: StreamReadConstraints.maxDocumentLength not checked when creating parser with fixed buffer
• #651: Ensure Smile backend supports StreamReadConstraints.maxTokenCount

YAML

• #610: Update to SnakeYAML 2.5