{"id":"CVE-2026-53935","aliases":["GHSA-q6h5-q3q6-f87x"],"title":"CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation","summary":"CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation","severity":"medium","cvss":6.9,"cwe":["CWE-601"],"vendor":"cilium","product":"github.com/cilium/cilium","ecosystem":"go","affected":["github.com/cilium/cilium >= 1.19.0, < 1.19.4","github.com/cilium/cilium >= 1.18.2, < 1.18.10","github.com/cilium/cilium < 1.17.16"],"patched":["github.com/cilium/cilium 1.19.4","github.com/cilium/cilium 1.18.10","github.com/cilium/cilium 1.17.16"],"published":"2026-07-06","updated":"2026-07-06","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-q6h5-q3q6-f87x","references":[{"url":"https://github.com/cilium/cilium/security/advisories/GHSA-q6h5-q3q6-f87x"},{"url":"https://github.com/cilium/cilium/pull/44512"},{"url":"https://github.com/cilium/cilium/pull/44584"},{"url":"https://github.com/cilium/cilium/pull/44585"},{"url":"https://github.com/advisories/GHSA-q6h5-q3q6-f87x"}],"tags":["ghsa","go"],"ingestedAt":"2026-07-06T20:46:12.545Z","epss":0.0034,"epssPercentile":0.2763,"slug":"CVE-2026-53935","body":"## Overview\n\n### Impact\n\nUsers 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.\n\nIn addition, deleting such a policy can corrupt Cilium's internal service state, causing service translation to stop working entirely for the affected Service.\n\n### Patches\n\nThis issue affects:\n\n- Cilium v1.19.0 to v1.19.3 inclusive  (fixed in PR #45584)\n- Cilium v1.18.2 to v1.18.9 inclusive (fixed in PR #45585)\n- All versions of Cilium prior to v1.17.16 (fixed in PR #45412)\n\nThis issue has been patched in:\n\n- Cilium v1.19.4\n- Cilium v1.18.10\n- Cilium v1.17.16\n\n### Workarounds\n\nThere is no workaround to this issue.\n\n### Acknowledgements\n\nThe Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @ysksuzuki for investigating and fixing the issue.\n\n### For more information\nIf there are any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/).\n\nTo report potential vulnerabilities affecting Cilium, it strongly is encouraged to report them through the security mailing list at [security@cilium.io](mailto:security@cilium.io). This is a private mailing list for the Cilium security team, and reports will be treated as a top priority.\n\n## Affected packages\n\n- `github.com/cilium/cilium >= 1.19.0, < 1.19.4`\n- `github.com/cilium/cilium >= 1.18.2, < 1.18.10`\n- `github.com/cilium/cilium < 1.17.16`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/cilium/cilium 1.19.4`\n- `github.com/cilium/cilium 1.18.10`\n- `github.com/cilium/cilium 1.17.16`","depth":"sunlit","depthScore":38,"depthScoreParts":{"impact":38,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}