CVE-2026-18107
NVD analysis in progress
A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore. A malicious process inside a container can register an rseq critical section that hijacks CRIU's parasite code injection during checkpoint, allowing it to spoof the process credentials saved in the checkpoint image. On restore, the container process gains elevated capabilities and zeroed UIDs/GIDs. The practical impact on Red Hat products is limited by several factors: checkpoint/restore requires root privileges (podman) or cluster-admin RBAC (OpenShift) to trigger and cannot be initiated from within the container itself; on OpenShift prior to 4.17 the feature required explicit opt-in, and on 4.17+ the kubelet checkpoint API RBAC is not configured by default; OpenShift enforces user namespaces by default for regular workloads (hostUsers is gated behind admin-only SCCs), which makes the spoofed capabilities namespace-scoped and ineffective for privilege escalation; SELinux type enforcement (container_t) blocks privilege transitions independently of capabilities; seccomp filters persist through checkpoint/restore and cannot be corrupted via the parasite; and kernel mount namespace ownership checks on RHEL 9/10 kernels prevent mount-based container escape even with spoofed capabilities.
What this means
- Exposure
- Exploitable with local access to the machine, with an ordinary user account and with no action from the victim. The attack does require particular conditions, which makes it less systematic.
- Impact
- An attacker can read sensitive data, modify or destroy data and take the service offline. The impact spreads beyond the vulnerable component into other parts of the system.
- Weakness
- Privilege handling is faulty, so an account ends up with more rights than intended.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.