CVE-2026-46680
Description
A flaw was found in containerd, an open-source container runtime. Containers launched with a numeric User directive that cannot be parsed as a 32-bit integer are incorrectly treated as a username. This vulnerability allows a crafted container image to bypass the Kubernetes runAsNonRoot restriction, potentially leading to privilege escalation where the container runs as the root user (UID 0). This can cause unexpected behavior in environments designed to enforce non-root user execution.
Statement
Red Hat OpenShift Container Platform and its layered products include the containerd Go library as a build-time dependency for various components. These products do not use containerd as a container runtime; CRI-O is used instead. The vulnerable code path responsible for parsing User directives during container runtime spec generation is not exercised. Therefore, although the containerd library is present in shipped binaries, the vulnerability is not exploitable in the context of Red Hat products.
Mitigation
Enforce a specific numeric runAsUser in the Kubernetes Pod securityContext, which overrides the User directive in the container image and prevents the bypass. Additionally, restrict access to push container images to trusted users only, and validate image provenance before deployment.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other,Integrity
Technical Impact: Unexpected State; Quality Degradation
The program could wind up using the wrong number and generate incorrect results. If the number is used to allocate resources or make a security decision, then this could introduce a vulnerability.
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