{"id":"CVE-2026-46680","aliases":["GHSA-fqw6-gf59-qr4w","GO-2026-5378"],"url":"https://o3.security/vulnerability/CVE-2026-46680","summary":"containerd user ID handling bypass allows runAsNonRoot evasion","details":"### Impact\nA bug was found in containerd where containers launched with a numeric `User` directive that cannot be parsed as a 32-bit integer are incorrectly treated as a username. If a crafted image provides an `/etc/passwd` file mapping this large numeric string to root, the container ultimately runs as root (UID 0). This allows the Kubernetes `runAsNonRoot` restriction to be bypassed, causing unexpected behavior for environments that require containers to run as a non-root user.\n\n### Patches\nThis bug has been fixed in the following containerd versions:\n\n* 2.3.1\n* 2.2.4\n* 2.0.9\n* 1.7.32\n\nNote: The containerd 2.1 release has reached its [end of life](https://containerd.io/releases/#current-state-of-containerd-releases) and a fixed version is not provided.\n\nUsers should update to these versions to resolve the issue.\n\n### Workarounds\nEnsure that only trusted images are used and that only trusted users have permissions to import images. Alternatively, enforcing a specific numeric `runAsUser` in the Kubernetes Pod `securityContext` overrides the `USER` directive in the image and prevents the bypass. Newer versions of Kubernetes, starting with 1.34, also appear to enforce `runAsNonRoot` properly regardless of this bug.\n\n### Credits\nThe containerd project would like to thank Lei Wang (@ssst0n3) for responsibly disclosing this issue in accordance with the [containerd security policy](https://github.com/containerd/project/blob/main/SECURITY.md).\n\n### Resources\n* https://github.com/advisories/GHSA-265r-hfxg-fhmg (CVE-2024-40635)\n\n### For more information\n\nIf there are any questions or comments about this advisory:\n\n* Open an issue in [containerd](https://github.com/containerd/containerd/issues/new/choose)\n* Send an email to [security@containerd.io](mailto:security@containerd.io)\n\nTo report a security issue in containerd:\n* [Report a new vulnerability](https://github.com/containerd/containerd/security/advisories/new)\n* Send an email to [security@containerd.io](mailto:security@containerd.io)","published":"2026-07-01T17:40:25.499Z","modified":"2026-08-12T03:51:26.564052474Z","cvss":null,"epss":{"score":0.00163,"percentile":0.05895,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/containerd/containerd","fixedVersion":"1.7.32"},{"ecosystem":"Go","name":"github.com/containerd/containerd/v2","fixedVersion":"2.0.9"},{"ecosystem":"Go","name":"github.com/containerd/containerd/v2","fixedVersion":"2.2.4"},{"ecosystem":"Go","name":"github.com/containerd/containerd/v2","fixedVersion":"2.3.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46680.json"},{"type":"ADVISORY","url":"https://github.com/containerd/containerd/security/advisories/GHSA-fqw6-gf59-qr4w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46680"},{"type":"PACKAGE","url":"https://github.com/containerd/containerd"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:26.564052474Z"}}