Amazon Linux 2023 : crit, criu, criu-devel (ALAS2023-2026-2126)

high Nessus Plugin ID 341885

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Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-2126 advisory.

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)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Run 'dnf update criu --releasever 2023.12.20260831' or or 'dnf update --advisory ALAS2023-2026-2126 --releasever 2023.12.20260831' to update your system.

Plugin Details

Severity: High

ID: 341885

File Name: al2023_ALAS2023-2026-2126.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/31/2026

Updated: 10/27/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7

Percentile: 98

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.7

Vector: CVSS2#AV:L/AC:H/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-18107

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:crit, p-cpe:/a:amazon:linux:criu-debuginfo, p-cpe:/a:amazon:linux:criu-debugsource, p-cpe:/a:amazon:linux:criu-devel, p-cpe:/a:amazon:linux:criu-libs-debuginfo, p-cpe:/a:amazon:linux:criu-libs, p-cpe:/a:amazon:linux:criu-ns, p-cpe:/a:amazon:linux:criu, p-cpe:/a:amazon:linux:python3-criu

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/31/2026

Vulnerability Publication Date: 7/28/2026

Reference Information

CVE: CVE-2026-18107

Detections

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