GHSA-vwf8-q6fw-4wcm
MEDIUMGHSA-vwf8-q6fw-4wcm is a medium-severity (CVSS 5.4) Information Exposure vulnerability in github.com/cilium/cilium. O3 Security confirms whether GHSA-vwf8-q6fw-4wcm is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cilium leaks information via incorrect ReferenceGrant update logic in Gateway API
Blast Radius
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
Due to ReferenceGrant changes not being immediately propagated in Cilium's GatewayAPI controller, Gateway resources are able to access secrets in other namespaces after the associated ReferenceGrant has been revoked. This can lead to Gateways continuing to establish sessions using secrets that they should no longer have access to.
Patches
This issue was resolved in https://github.com/cilium/cilium/pull/34032.
This issue affects:
- Cilium v1.15 between v1.15.0 and v1.15.7 inclusive
- Cilium v1.16.0
This issue has been patched in:
- Cilium v1.15.8
- Cilium v1.16.1
Workarounds
Any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster.
Acknowledgements
The Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for resolving this issue.
For more information
If you have any questions or comments about this advisory, please reach out on Slack.
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [email protected]. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cilium/cilium | ≥ 1.16.0&&< 1.16.1 | 1.16.1 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.15.0&&< 1.15.8 | 1.15.8 |
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 1.16.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vwf8-q6fw-4wcm 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-vwf8-q6fw-4wcm 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-vwf8-q6fw-4wcm. 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-vwf8-q6fw-4wcm in your dependencies?
O3 detects GHSA-vwf8-q6fw-4wcm across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.