Incomplete seccomp deny rules in containers-common allow bypass
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The default seccomp profile used by Podman via containers-common has deny rules for AF_VSOCK and NETLINK_AUDIT sockets that compare arguments without masking. Because the kernel truncates these arguments to 32 bits, setting the upper bits bypasses the rules (CWE-184). A local user with low privileges can bypass the deny rules, which has a low impact on confidentiality and integrity.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | No fix listed | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 5 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:hummingbird:1 | 1 | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
| cpe:/a:redhat:openshift:5 | 5 | — | Red Hat |
- cpe:/a:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
- cpe:/a:redhat:openshift:5 Versions 5 — ·Red Hat
Remediation
The sources list no fixed version for Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, Red Hat Hardened Images, Red Hat OpenShift Container Platform 4 or Red Hat OpenShift Container Platform 5. Red Hat lists no available fix plan for these products, and Red Hat Enterprise Linux 8 is not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Hardened Images | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 8
- Red Hat Hardened Images
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-11-06 Threatist record created from CVE-2026-123876
- 2026-11-06 Alias added: GHSA-2fgp-24rx-f2r7
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · CNA
- 2026-11-07 Affected versions changed · Red Hat
References
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Sources
- CVE-2026-123876 · CVE Program
- CVE-2026-123876 · NVD
- FIRST EPSS
- GHSA-2fgp-24rx-f2r7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-123876 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences