GHSA-2h44-x2wx-49f4
MEDIUMPotential HTTP policy bypass when using header rules in Cilium
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.
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
This issue only impacts users who:
- Have a HTTP policy that applies to multiple
toEndpointsAND - Have an allow-all rule in place that affects only one of those endpoints
In such cases, a wildcard rule will be appended to the set of HTTP rules, which could cause bypass of HTTP policies.
Patches
This issue has been patched in Cilium 1.11.16, 1.12.9, and 1.13.2.
Workarounds
Rewrite HTTP rules for each endpoint separately. For example, if the initial rule looks like:
egress:
- toEndpoints:
- matchLabels:
k8s:kind: echo
- matchLabels:
k8s:kind: example
toPorts:
- ports:
- port: "8080"
protocol: TCP
rules:
http:
- method: "GET"
It should be rewritten to:
egress:
- toEndpoints:
- matchLabels:
k8s:kind: echo
toPorts:
- ports:
- port: "8080"
protocol: TCP
rules:
http:
- method: "GET"
- toEndpoints:
- matchLabels:
k8s:kind: example
toPorts:
- ports:
- port: "8080"
protocol: TCP
rules:
http:
- method: "GET"
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @jrajahalme for investigating and fixing the issue.
For more information
If you have any questions or comments about this advisory, please reach out on Slack.
As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: [email protected] - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cilium/cilium | all versions | 1.11.16 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.12.0&&< 1.12.9 | 1.12.9 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.13.0&&< 1.13.2 | 1.13.2 |
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 1.11.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2h44-x2wx-49f4 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-2h44-x2wx-49f4 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-2h44-x2wx-49f4. 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-2h44-x2wx-49f4 in your dependencies?
O3 detects GHSA-2h44-x2wx-49f4 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.