6.5
Medium
org.springframework.kafka:spring-kafka

CVE-2026-41726

CVE-2026-41726 is a medium-severity allocation of resources without limits or throttling vulnerability in org.springframework.kafka:spring-kafka (maven), affecting versions >= 4.0.0, <= 4.0.5. It is fixed in 4.0.6, 3.3.16.

Key facts
CVSS score
6.5
Medium
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
org.springframework.kafka:spring-kafka
Fixed in
4.0.6, 3.3.16
Disclosed
2026

Summary

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. Affected versions: 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.

Impact

What is allocation of resources without limits or throttling?

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

Severity and exposure

CVE-2026-41726 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (4.0.6, 3.3.16). Upgrading removes the vulnerable code path.

Affected versions

maven

  • org.springframework.kafka:spring-kafka (>= 4.0.0, <= 4.0.5)
  • org.springframework.kafka:spring-kafka (>= 3.3.0, <= 3.3.15)
  • org.springframework.kafka:spring-kafka (>= 3.2.0, <= 3.2.13)
  • org.springframework.kafka:spring-kafka (>= 2.9.0, <= 2.9.13)
  • org.springframework.kafka:spring-kafka (<= 2.8.11)

Security releases

  • org.springframework.kafka:spring-kafka → 4.0.6 (maven)
  • org.springframework.kafka:spring-kafka → 3.3.16 (maven)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2026-41726 is reachable in your applications. Explore open-source security for your team.

See if CVE-2026-41726 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade org.springframework.kafka:spring-kafka to 4.0.6 or later
  • Upgrade org.springframework.kafka:spring-kafka to 3.3.16 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-41726

What is CVE-2026-41726?

CVE-2026-41726 is a medium-severity allocation of resources without limits or throttling vulnerability in org.springframework.kafka:spring-kafka (maven), affecting versions >= 4.0.0, <= 4.0.5. It is fixed in 4.0.6, 3.3.16. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.

How severe is CVE-2026-41726?

CVE-2026-41726 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of org.springframework.kafka:spring-kafka are affected by CVE-2026-41726?

org.springframework.kafka:spring-kafka (maven) versions >= 4.0.0, <= 4.0.5 is affected.

Is there a fix for CVE-2026-41726?

Yes. CVE-2026-41726 is fixed in 4.0.6, 3.3.16. Upgrade to this version or later.

Is CVE-2026-41726 exploitable, and should I be worried?

Whether CVE-2026-41726 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-41726 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-41726?
  • Upgrade org.springframework.kafka:spring-kafka to 4.0.6 or later
  • Upgrade org.springframework.kafka:spring-kafka to 3.3.16 or later

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