Executive brief
CRI-O is a container runtime used in Kubernetes environments to execute and manage containers. A vulnerability in its checkpoint restore feature allows an attacker with permission to create pods to bypass Kubernetes security policies and execute containers with elevated privileges (root and full capabilities), even when the pod specification requires restricted permissions. This can be exploited remotely by pulling a malicious checkpoint image from a registry.
Technical details
The vulnerability exists in CRI-O's checkpoint restore implementation, which fails to enforce the destination Kubernetes security context when restoring from checkpointed container images. Instead, CRIU restores process credentials, Linux capabilities, no_new_privs bit, and seccomp state directly from the checkpoint archive, allowing an attacker to craft a malicious checkpoint image that executes with root privileges and full capabilities regardless of the pod's specified security context. Attack requires pod creation privileges and checkpoint restore functionality enabled (not enabled by default in OpenShift but enabled by default in standalone CRI-O).
Affected products
- CRI-O CRI-O 1.34 and later
- Red Hat OpenShift Container Platform 4.17 and later
Timeline
- 2026-09-21: disclosed
- other: Fixes applied to supported branches but not yet released