Gateway API route matching order contradicts specification (CVE-2024-42487)

Why this deserves its current priority

CVSS is 4.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps github.com/cilium/cilium (go), github.com/cilium/cilium (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
github.com/cilium/ciliumgo	>=1.16.0 <1.16.1	1.16.1
github.com/cilium/ciliumgo	>=1.15.0 <1.15.8	1.15.8

Recommended response

Check inventory. Check lockfiles and deployed manifests for github.com/cilium/cilium, github.com/cilium/cilium.
Review the reported fix. Update github.com/cilium/cilium to 1.16.1; github.com/cilium/cilium to 1.15.8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 15, 2024
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source 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](https://gateway-api.sigs.k8s.io/reference/spec/#gateway.networking.k8s.io/v1.HTTPRouteRule), [GRPCRouteRule](https://gateway-api.sigs.k8s.io/reference/spec/#gateway.networking.k8s.io%2fv1.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](https://docs.cilium.io/en/latest/community/community/#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]](mailto:[email protected]). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Quoted source text, attributed separately from HOL analysis.