GHSA-28jg-cgg7-j4wc
CRITICALGHSA-28jg-cgg7-j4wc is a critical-severity (CVSS 9.1) CWE-1285 vulnerability in org.apache.kafka:kafka-clients. O3 Security confirms whether GHSA-28jg-cgg7-j4wc is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache Kafka does not validate JWT tokens in its OAUTHBEARER authentication implementation
Blast Radius
org.apache.kafka:kafka-clientsReal-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
A security vulnerability has been identified in Apache Kafka. By default, the broker property sasl.oauthbearer.jwt.validator.class is set to org.apache.kafka.common.security.oauthbearer.DefaultJwtValidator. It accepts any JWT token without validating its signature, issuer, or audience. An attacker can generate a JWT token from any issuer with the preferred_username set to any user, and the broker will accept it.
Apache advises Kafka users using kafka v4.1.0 or v4.1.1 to set the config sasl.oauthbearer.jwt.validator.class to org.apache.kafka.common.security.oauthbearer.BrokerJwtValidator explicitly to avoid this vulnerability. Since Kafka v4.1.2 and v4.2.0 and later, the issue is fixed and will correctly validate the JWT token.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.kafka:kafka-clients | ≥ 4.1.0&&< 4.1.2 | 4.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.kafka:kafka-clients. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.kafka:kafka-clients to 4.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-28jg-cgg7-j4wc 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.
How O3 protects you
O3 pinpoints whether GHSA-28jg-cgg7-j4wc is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-28jg-cgg7-j4wc. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-28jg-cgg7-j4wc in your dependencies?
O3 detects GHSA-28jg-cgg7-j4wc across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.