CVE-2026-41726 is a medium-severity (CVSS 6.5) CWE-770 vulnerability in org.springframework.kafka:spring-kafka. A fix is available for org.springframework.kafka:spring-kafka — see the affected versions and patch details below.
In Spring for Apache Kafka, unbounded delegate cache keyed on user-controlled, potentially malicious selector header
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-41726.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-41726 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.springframework.kafka:spring-kafka☕org.springframework.kafka:spring-kafka☕org.springframework.kafka:spring-kafka☕org.springframework.kafka:spring-kafka☕org.springframework.kafka:spring-kafkaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.springframework.kafka:spring-kafka | ≥ 4.0.0&&< 4.0.6 | 4.0.6org.springframework.kafka:spring-kafka:4.0.6 |
| ☕Maven | org.springframework.kafka:spring-kafka | ≥ 3.3.0&&< 3.3.16 | 3.3.16org.springframework.kafka:spring-kafka:3.3.16 |
| ☕Maven | org.springframework.kafka:spring-kafka | ≥ 3.2.0 | No fix |
| ☕Maven | org.springframework.kafka:spring-kafka | ≥ 2.9.0 | No fix |
| ☕Maven | org.springframework.kafka:spring-kafka | all versions | No fix |
Affected Products
spring for apache kafkavmwareDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework.kafka:spring-kafka, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.springframework.kafka:spring-kafka to 4.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41726 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-41726 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-41726 in your dependencies?
Find it across Maven, including transitive dependencies.