GHSA-q6h5-q3q6-f87x
MEDIUMCiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
Blast Radius
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.