CVE-2026-123876: CWE-184
Source GCVE Database
Not known to be exploited · CVSS 4.4 Medium.
Data as of 6 Nov 2026, 19:04 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 4.4 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10containers-common | Affected– | Fixed in– |
| Red Hat Enterprise Linux 8container-tools:rhel8/containers-common | Affected– | Fixed in– |
| Red Hat Enterprise Linux 9containers-common | Affected– | Fixed in– |
| Red Hat Hardened Imagescontainers-common | Affected– | Fixed in– |
| Red Hat Hardened Imagespodman | Affected– | Fixed in– |
| Red Hat Hardened Imagesskopeo | Affected– | Fixed in– |
AI-suggested
Red Hat advises not to rely on the unfixed seccomp deny rules alone. Enforcing SELinux may still deny vsock usage, providing some mitigation. The recommended approach is to deploy updated seccomp profiles that use SCMP_CMP_MASKED_EQ comparisons to correctly handle argument masking. Users should monitor Red Hat advisories for official patches or updated profiles.
Description
A vulnerability exists in the default seccomp profile used by Podman via containers-common, where deny rules for AF_VSOCK and NETLINK_AUDIT sockets compare arguments using unmasked 64-bit equality. The Linux kernel truncates these arguments to 32 bits, allowing attackers to bypass the deny rules by setting upper bits. This flaw can lead to bypassing intended security restrictions in container environments.
References
- nvd.nist.gov/vuln/detail/CVE-2026-123876 (opens in a new tab)
- github.com/podman-container-tools/container-libs/issues/1248 (opens in a new tab)
- github.com/podman-container-tools/container-libs/pull/1249 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-123876 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2566536 (opens in a new tab)
- openwall.com/lists/oss-security/2026/10/27/3 (opens in a new tab)