GHSA-q6h5-q3q6-f87x is a medium-severity (CVSS 6.9) CWE-863 vulnerability in github.com/cilium/cilium. O3 Security confirms whether GHSA-q6h5-q3q6-f87x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
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 GHSA-q6h5-q3q6-f87x.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-q6h5-q3q6-f87x plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/cilium/cilium🐹github.com/cilium/cilium🐹github.com/cilium/ciliumReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Users with the ability to create CiliumLocalRedirectPolicies can specify arbitrary ClusterIPs via addressMatcher, which enables hijacking traffic to Services in any namespace, bypassing the namespace-scoping guarantees enforced by serviceMatcher.
In addition, deleting such a policy can corrupt Cilium's internal service state, causing service translation to stop working entirely for the affected Service.
Patches
This issue affects:
- Cilium v1.19.0 to v1.19.3 inclusive (fixed in PR #45584)
- Cilium v1.18.2 to v1.18.9 inclusive (fixed in PR #45585)
- All versions of Cilium prior to v1.17.16 (fixed in PR #45412)
This issue has been patched in:
- Cilium v1.19.4
- Cilium v1.18.10
- Cilium v1.17.16
Workarounds
There is no workaround to this issue.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @ysksuzuki for investigating and fixing the issue.
For more information
If there are any questions or comments about this advisory, please reach out on Slack.
To report potential vulnerabilities affecting Cilium, it strongly is encouraged to report them through the security mailing list at [email protected]. This is a private mailing list for the Cilium security team, and reports will be treated as a top priority.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cilium/cilium | ≥ 1.19.0&&< 1.19.4 | 1.19.4 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.18.2&&< 1.18.10 | 1.18.10 |
| 🐹Go | github.com/cilium/cilium | all versions | 1.17.16 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium. 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 github.com/cilium/cilium to 1.19.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q6h5-q3q6-f87x 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-q6h5-q3q6-f87x 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-q6h5-q3q6-f87x. 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-q6h5-q3q6-f87x in your dependencies?
O3 detects GHSA-q6h5-q3q6-f87x across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.