Description

JsonKafkaHeaderMapper and the deprecated DefaultKafkaHeaderMapper matched type headers against trusted packages using a prefix check, meaning that trusting any package implicitly trusted all of its subpackages. Combined with Jackson's default bean deserialization, a producer could supply crafted header values that caused the consumer to deserialize arbitrary JDK types, including classes whose constructors carry side effects such as allocating file descriptors or spawning thread pools.

Affected Spring Products and Versions

Spring for Apache Kafka:

• 4.0.0 - 4.0.5
• 3.3.0 - 3.3.15
• 3.2.0 - 3.2.13
• 2.9.0 - 2.9.13
• 2.8.0 - 2.8.11

Versions that are no longer supported are also affected.

Mitigation

Users of affected versions should upgrade to the corresponding fixed version.

No further mitigation steps are necessary.

Credit

This issue was discovered internally.

References

• https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H&version=3.1

History

• 2026-06-09: Initial vulnerability report published.