CVE-2026-123876
Podman: containers-common: containers-common: default seccomp af_vsock/netlink_audit deny rules bypassable via 32-bit truncation
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.
Fixes and workarounds
Workaround
Enforcing SELinux may still deny vsock; do not rely on the unfixed seccomp denies; ship SCMP_CMP_MASKED_EQ profile updates.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Enterprise Linux 10 Red Hat containers-common
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8 Red Hat container-tools:rhel8/containers-common
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat containers-common
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Hardened Images Red Hat containers-common
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat Hardened Images Red Hat podman
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Hardened Images Red Hat skopeo
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat containers-common
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 5 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 4.4 medium |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N | CNA: redhat |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://access.redhat.com/security/cve/CVE-2026-123876CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2566536CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://github.com/podman-container-tools/container-libs/issues/1248CNA: redhat
- https://github.com/podman-container-tools/container-libs/pull/1249CNA: redhat
- https://www.openwall.com/lists/oss-security/2026/10/27/3CNA: redhat
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