VYPR
← All advisories
High severityGHSA Advisory· Published May 21, 2026

containerd user ID handling bypass allows runAsNonRoot evasion

CVE-2026-46680

Description

Impact

A 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.

Patches

This bug has been fixed in the following containerd versions:

  • 2.3.1
  • 2.2.4
  • 2.0.9
  • 1.7.32

Note: The containerd 2.1 release has reached its end of life and a fixed version is not provided.

Users should update to these versions to resolve the issue.

Workarounds

Ensure 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.

Credits

The containerd project would like to thank Lei Wang (@ssst0n3) for responsibly disclosing this issue in accordance with the containerd security policy.

### Resources * https://github.com/advisories/GHSA-265r-hfxg-fhmg (CVE-2024-40635)

For more information

If there are any questions or comments about this advisory:

To report a security issue in containerd: * Report a new vulnerability * Send an email to security@containerd.io

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
github.com/containerd/containerdGo
>= 1.7.27, < 1.7.321.7.32
github.com/containerd/containerd/v2Go
>= 2.0.4, < 2.0.92.0.9
github.com/containerd/containerd/v2Go
>= 2.1.0-beta.0, < 2.2.42.2.4
github.com/containerd/containerd/v2Go
>= 2.3.0-beta.0, < 2.3.12.3.1

Affected products

315

Patches

Vulnerability mechanics

References

2

News mentions

0

No linked articles in our index yet.