PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-41731 Spring CVE debrief

CVE-2026-41731 is a HIGH severity vulnerability in Spring for Apache Kafka. The JsonKafkaHeaderMapper and the deprecated DefaultKafkaHeaderMapper matched type headers against trusted packages using a prefix check. This meant 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. Affected versions include Spring for Apache Kafka 4.0.0 through 4.0.5; 3.3.0 through 3.3.15; 3.2.0 through 3.2.13; 2.9.0 through 2.9.13; 2.8.0 through 2.8.11.

Vendor
Spring
Product
Spring for Apache Kafka
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-10
Original CVE updated
2026-08-05
Advisory published
2026-06-10
Advisory updated
2026-08-05

Who should care

Users of Spring for Apache Kafka, particularly those using versions 4.0.0 through 4.0.5; 3.3.0 through 3.3.15; 3.2.0 through 3.2.13; 2.9.0 through 2.9.13; 2.8.0 through 2.8.11, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability arises from the prefix check used by JsonKafkaHeaderMapper and DefaultKafkaHeaderMapper to match type headers against trusted packages. This allows for a producer to supply crafted header values that can cause the consumer to deserialize arbitrary JDK types when combined with Jackson's default bean deserialization.

Defensive priority

HIGH

Recommended defensive actions

  • Update to a version of Spring for Apache Kafka that is not vulnerable: 4.0.6 or later, 3.3.16 or later, 3.2.14 or later, 2.9.14 or later, 2.8.12 or later.
  • Use a different header mapper that does not rely on prefix checks for trusted packages.

Evidence notes

The CVE was published on 2026-06-10T00:16:52.597Z and last modified on 2026-06-10T19:24:04.320Z. The CVSS score is 8.1, indicating a HIGH severity vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-41731 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-41731

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-41731 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-41731

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.