---
id: CVE-2026-123876
title: >-
  Podman: containers-common: containers-common: default seccomp
  af_vsock/netlink_audit deny rules bypassable via 32-bit truncation
summary: >-
  A flaw was found in the default seccomp profile used by Podman via
  containers-common. Deny rules for AF_VSOCK and NETLINK_AUDIT compared socket
  arguments with unmasked 64-bit equality. Because the kernel truncates those
  int arguments to …
severity: medium
cvss: 4.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-184
vendor: Red Hat
product: containers-common
affected:
  - containers-common (all versions)
  - 'container-tools:rhel8/containers-common (all versions)'
  - containers-common (all versions)
  - containers-common
  - podman (all versions)
  - skopeo
  - containers-common (all versions)
  - openshift/ose-rhel-coreos-8 (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
published: '2026-11-06'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:38:41.186Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123876'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-123876'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2566536'
    label: RHBZ#2566536
  - url: 'https://github.com/podman-container-tools/container-libs/issues/1248'
  - url: 'https://github.com/podman-container-tools/container-libs/pull/1249'
  - url: 'https://www.openwall.com/lists/oss-security/2026/10/27/3'
tags:
  - cve.org
ingestedAt: '2026-11-06T18:00:12.510Z'
---

## Overview

A flaw was found in the default seccomp profile used by Podman via containers-common. Deny rules for AF_VSOCK and NETLINK_AUDIT compared socket arguments with unmasked 64-bit equality. Because the kernel truncates those int arguments to 32 bits, setting upper bits can bypass the deny rules.

## Affected

- `containers-common (all versions)`
- `container-tools:rhel8/containers-common (all versions)`
- `containers-common (all versions)`
- `containers-common`
- `podman (all versions)`
- `skopeo`
- `containers-common (all versions)`
- `openshift/ose-rhel-coreos-8 (all versions)`
- `openshift/ose-rhel-coreos-9 (all versions)`
- `openshift/ose-rhel-coreos-9 (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

Enforcing SELinux may still deny vsock; do not rely on the unfixed seccomp denies; ship SCMP_CMP_MASKED_EQ profile updates.