CVE-2026-53935

### 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](https://docs.cilium.io/en/latest/community/community/). To report potential vulnerabilities affecting Cilium, it strongly is encouraged to report them through the security mailing list at [[email protected]](mailto:[email protected]). This is a private mailing list for the Cilium security team, and reports will be treated as a top priority.