{"id":"CVE-2026-41520","aliases":["BIT-cilium-2026-41520","BIT-cilium-operator-2026-41520","BIT-hubble-relay-2026-41520","GHSA-gj49-89wh-h4gj","GO-2026-5400"],"url":"https://o3.security/vulnerability/CVE-2026-41520","summary":"Cillium exposes sensitive information included in the cilium-bugtool debug archive","details":"### Impact\nThe output of `cilium-bugtool` can contain sensitive data when the tool is run against Cilium deployments with WireGuard encryption enabled.\n\nUsers of [WireGuard Transparent Encryption](https://docs.cilium.io/en/stable/security/network/encryption-wireguard/) are affected.\nThe sensitive data is  the WireGuard private key (`cilium_wg0.key`) used for node-to-node encrypted communication\n\n`cilium-bugtool` is a debugging tool that is typically invoked manually and does not run during the normal operation of a Cilium cluster. It is also invoked when gathering sysdumps using the Cilium CLI's `cilium sysdump` command.\n\n### Patches\nThis issue affects:\n\n- Cilium v1.19 between v1.19.0 and v1.19.2 inclusive\n- Cilium v1.18 between v1.18.0 and v1.18.8 inclusive\n- All versions of Cilium prior to v1.17.15\n\nThis issue has been patched in:\n\n- Cilium v1.19.3\n- Cilium v1.18.9\n- Cilium v1.17.15\n\n\n### Workarounds\nThere is no workaround to this issue.\n\nUsers who have previously shared bugtool or sysdump archives from WireGuard-enabled nodes should rotate the WireGuard keys on the affected nodes. This can be done by deleting the key file and restarting the Cilium agent, which will generate a new key pair.\n\n### Acknowledgements\n\nThe Cilium community has worked together with members of Isovalent to prepare these mitigations. Cillium extends special thanks to @kodareef5  for reporting the issue and  @tklauser for their work on triaging and remediating this issue.\n\n### For more information\n\nIf there are any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/).\n\nCilium strongly encourages the reporting of suspected vulnerabilities to the security mailing list at [security@cilium.io](mailto:security@cilium.io). This is a private mailing list for the Cilium security team, and the report will be treated as top priority.","published":"2026-05-08T22:01:08.394Z","modified":"2026-10-28T02:30:34.892876097Z","cvss":{"score":7.9,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N"},"epss":{"score":0.00077,"percentile":0.00121,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.17.15"},{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.18.9"},{"ecosystem":"Go","name":"github.com/cilium/cilium","fixedVersion":"1.19.3"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.17.15"},{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.18.9"},{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.19.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41520.json"},{"type":"ADVISORY","url":"https://github.com/cilium/cilium/security/advisories/GHSA-gj49-89wh-h4gj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41520"},{"type":"PACKAGE","url":"https://github.com/cilium/cilium"},{"type":"WEB","url":"http://docs.cilium.io/en/stable/security/network/encryption-wireguard"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:34.892876097Z"}}