CVE-2024-42487 is a medium-severity (CVSS 4) CWE-113 vulnerability in github.com/cilium/cilium. A fix is available for github.com/cilium/cilium — see the affected versions and patch details below.
Cilium's Gateway API route matching order contradicts specification
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 CVE-2024-42487.
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
CVE-2024-42487 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 378,567 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/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
Gateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched (HTTPRouteRule, GRPCRouteRule).
If users create Gateway API resources that use both request headers and request methods in order to route to different destinations, then traffic may be delivered to the incorrect backend. If the backend does not have Network Policy restricting acceptable traffic to receive, then requests may access information that you did not intend for them to access.
Patches
This issue was fixed in https://github.com/cilium/cilium/pull/34109.
This issue affects:
- Cilium v1.15 between v1.15.0 and v1.15.7 inclusive
- Cilium v1.16.0
This issue is fixed in:
- Cilium v1.15.8
- Cilium v1.16.1
Workarounds
There is no workaround for this issue.
Acknowledgements
The Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for remediating this issue.
Further 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 | 1.16.1go get github.com/cilium/cilium@v1.16.1 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.15.0&&< 1.15.8 | 1.15.8go get github.com/cilium/cilium@v1.15.8 |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 CVE-2024-42487 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-42487 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-42487. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-42487 in your dependencies?
O3 Security finds CVE-2024-42487 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.