# CVE-2026-18107: criu: A flaw was found in CRIU's handling of restartable sequences (rseq) during checkpoint/restore

CVE-2026-18107 is fixed in 9 products on 1 platform, first by DEBIAN-CVE-2026-18107, released July 31, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-18107
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 28, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | crit amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu Debian 14 | 4.2-5 | [DEBIAN-CVE-2026-18107](https://patchblox.com/security/data/fix/linux/debian-cve-2026-18107.md) | Jul 31, 2026 |
| Linux | criu amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-debuginfo amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-debugsource amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-devel amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-libs amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-libs-debuginfo amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | criu-ns amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |
| Linux | python3-criu amzn 2023 | 3.17.1-1.amzn2023.0.4 | [ALAS2023-2026-2126](https://patchblox.com/security/data/fix/linux/alas2023-2026-2126.md) | Aug 31, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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