Amazon Linux 2023 Security Advisory: ALAS2023-2026-2126
Advisory Released Date: 2026-08-31
Advisory Updated Date: 2026-08-31
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. (CVE-2026-18107)
Affected Packages:
criu
Issue Correction:
Run dnf update criu --releasever 2023.12.20260831 or dnf update --advisory ALAS2023-2026-2126 --releasever 2023.12.20260831 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
aarch64:
criu-debuginfo-3.17.1-1.amzn2023.0.4.aarch64
criu-devel-3.17.1-1.amzn2023.0.4.aarch64
criu-ns-3.17.1-1.amzn2023.0.4.aarch64
criu-3.17.1-1.amzn2023.0.4.aarch64
criu-libs-3.17.1-1.amzn2023.0.4.aarch64
criu-debugsource-3.17.1-1.amzn2023.0.4.aarch64
criu-libs-debuginfo-3.17.1-1.amzn2023.0.4.aarch64
crit-3.17.1-1.amzn2023.0.4.aarch64
python3-criu-3.17.1-1.amzn2023.0.4.aarch64
src:
criu-3.17.1-1.amzn2023.0.4.src
x86_64:
criu-debuginfo-3.17.1-1.amzn2023.0.4.x86_64
criu-ns-3.17.1-1.amzn2023.0.4.x86_64
criu-libs-3.17.1-1.amzn2023.0.4.x86_64
criu-libs-debuginfo-3.17.1-1.amzn2023.0.4.x86_64
crit-3.17.1-1.amzn2023.0.4.x86_64
criu-debugsource-3.17.1-1.amzn2023.0.4.x86_64
criu-devel-3.17.1-1.amzn2023.0.4.x86_64
python3-criu-3.17.1-1.amzn2023.0.4.x86_64
criu-3.17.1-1.amzn2023.0.4.x86_64