CVE-2026-18107 Criu: criu: container escape via rseq critical section hijack during checkpoint/restore
A malicious container process can hijack CRIU checkpointing to spoof credentials, potentially gaining elevated capabilities upon restore.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18107?
CVE-2026-18107 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 28 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-269
Which versions are affected by CVE-2026-18107?
How do I fix CVE-2026-18107?
Apply the vendor's patch.
Is CVE-2026-18107 being exploited?
There is no known exploitation of CVE-2026-18107 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as AZL-94154, DEBIAN-CVE-2026-18107, GHSA-hm7v-8wcp-3gjm, UBUNTU-CVE-2026-18107.