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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-123876- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-184
- Updated
- 2026-11-06
EUVDEUVD-2026-118387
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.
- Record
EUVD-2026-118387- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-06
GitHub AdvisoriesGHSA-2fgp-24rx-f2r7
A flaw was found in the default seccomp profile used by Podman via containers-common. Deny rules...
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.
- Record
GHSA-2fgp-24rx-f2r7- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-184
- Updated
- 2026-11-06
NVD
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.
- Record
CVE-2026-123876- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-184
- Updated
- 2026-11-07
OSVDEBIAN-CVE-2026-123876
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.
- Record
DEBIAN-CVE-2026-123876- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-07
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
podmanDebian:13 |
All versions, plus listed versions 5.4.2+ds1-25.6.1+ds1-15.6.1+ds1-25.6.1+ds2-25.6.1+ds2-3 Show 22 moreShow less5.6.2+ds1-15.6.2+ds1-25.6.2+ds1-35.6.2+ds1-3+exp15.6.2+ds1-45.7.0+ds2-15.7.0+ds2-25.7.0+ds2-35.8.0+ds1-15.8.1+ds1-15.8.1+ds1-25.8.1+ds1-35.8.2+ds1-15.8.2+ds1-25.8.2+ds1-35.8.3+ds1-15.8.4+ds1-15.8.4+ds1-25.8.6+ds1-15.8.6+ds1-25.8.6+ds1-36.1.1+ds1-1 |
None known |
podmanDebian:14 |
All versions, plus listed versions 5.4.2+ds1-25.6.1+ds1-15.6.1+ds1-25.6.1+ds2-25.6.1+ds2-3 Show 22 moreShow less5.6.2+ds1-15.6.2+ds1-25.6.2+ds1-35.6.2+ds1-3+exp15.6.2+ds1-45.7.0+ds2-15.7.0+ds2-25.7.0+ds2-35.8.0+ds1-15.8.1+ds1-15.8.1+ds1-25.8.1+ds1-35.8.2+ds1-15.8.2+ds1-25.8.2+ds1-35.8.3+ds1-15.8.4+ds1-15.8.4+ds1-25.8.6+ds1-15.8.6+ds1-25.8.6+ds1-36.1.1+ds1-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | CVE List, NVD, OSV | |
| published | EUVD | |
| published | EUVD, NVD | |
| aliases, published | EUVD | |
| aliases, references | GitHub Advisories | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-123876 is a medium vulnerability (CVSS 4.4) in Red Hat Enterprise Linux 10, published November 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.15%, the 4th percentile. No source names a fixed version.
References
access.redhat.com/security/cve/CVE-2026-123876
bugzilla.redhat.com/show_bug.cgi?id=2566536
github.com/podman-container-tools/container-libs/issues/1248
openwall.com/lists/oss-security/2026/10/27/3
nvd.nist.gov/vuln/detail/CVE-2026-123876
security-tracker.debian.org/tracker/CVE-2026-123876