PatchSiren cyber security CVE debrief
CVE-2026-18107 Red Hat CVE debrief
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.
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 10
- CVSS
- HIGH 7.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-28
- Original CVE updated
- 2026-08-21
- Advisory published
- 2026-07-28
- Advisory updated
- 2026-08-21
Who should care
Container administrators, security teams, and users of Red Hat products, particularly those using OpenShift and podman, should be aware of this vulnerability and take necessary actions to protect their systems.
Technical summary
The vulnerability in CRIU's handling of restartable sequences (rseq) during checkpoint/restore allows a malicious process inside a container to hijack CRIU's parasite code injection. This can lead to spoofed process credentials in the checkpoint image, potentially allowing elevated capabilities and zeroed UIDs/GIDs upon restore. The impact is limited by several factors including required privileges for checkpoint/restore, OpenShift's user namespace enforcement, SELinux type enforcement, and kernel mount namespace ownership checks.
Defensive priority
Container administrators and security teams should verify their systems' configurations and apply patches as available, focusing on CRIU's checkpoint/restore functionality and related security features.
Recommended defensive actions
- Verify system configurations for CRIU's checkpoint/restore functionality
- Apply patches as available from Red Hat
- Review and update OpenShift and podman configurations to ensure proper security settings
- Monitor for suspicious activity related to container privilege escalation
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
- Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
- Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
Evidence notes
The CVE record and NVD entry provide details on the vulnerability, including its CVSS score of 7.8 and HIGH severity. Red Hat has provided references to their security advisory and bugzilla entry for further information.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-28T19:17:32.420Z and has not been modified since then. The NVD entry is currently Awaiting Analysis.