CVE-2026-41727 — spring-kafka
MEDIUMCVE-2026-41727 is a medium-severity (CVSS 6.5) Improper Input Validation 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, forged retry topic headers subvert retry routing and backoff behavior
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-2026-41727.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-41727 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 379,842 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
Spring Kafka's retry topic infrastructure did not sufficiently validate user-controlled header values before acting on them. A producer could send a record with a crafted retry_topic-attempts header to supply an out-of-range attempt count and cause the retry topic router to misidentify where the message was in the retry sequence.
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-2026-41727 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-41727 in your dependencies?
Find it across Maven, including transitive dependencies.