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CVE-2026-41726 Spring CVE debrief

CVE-2026-41726 is a MEDIUM-severity vulnerability affecting Spring for Apache Kafka. When an application opts into DelegatingDeserializer, a producer can grow the consumer's heap without bound by sending records with unique random spring.kafka.serialization.selector header values, eventually causing GC thrash and OutOfMemoryError. The affected versions are 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
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-10
Original CVE updated
2026-07-17
Advisory published
2026-06-10
Advisory updated
2026-07-17

Who should care

Users of Spring for Apache Kafka, particularly those who have applications that use DelegatingDeserializer, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by the lack of bounds checking on the spring.kafka.serialization.selector header values. This allows a producer to send records with unique random values, causing the consumer's heap to grow without bound.

Defensive priority

MEDIUM

Recommended defensive actions

  • Upgrade to a non-affected version of Spring for Apache Kafka.
  • Avoid using DelegatingDeserializer if possible.
  • Implement bounds checking on spring.kafka.serialization.selector header values.

Evidence notes

The CVE record and NVD detail pages provide additional information about this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-41726 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-41726

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

  • CVE-2026-41726 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-41726

    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.