CVE-2026-18107
HIGH 7.8A 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.
Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 2nd percentile
Impact if exploited
7.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-18107/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-18107/poc.json
Affected
Vendors Red Hat
Products Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Red Hat Openshift Container Platform 4
Weakness (CWE)
- CWE-269: Improper Privilege Management
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
All CVSS metrics
- HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H - HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H