VulnerabilityPublished 6 Nov 2026

CVE-2026-123876: Red Hat Enterprise Linux 10 · Incomplete List of Disallowed Inputs

Affects Red Hat Enterprise Linux 10Source CVE Database V5

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Not known to be exploited · CVSS 4.4 Medium.

Data as of 6 Nov 2026, 17:55 UTC

CVSS 3.1 base score

4.4Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
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:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

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 solely on the current unfixed seccomp deny rules. Enforcing SELinux may still block vsock usage. The recommended mitigation is to deploy updated seccomp profiles that use SCMP_CMP_MASKED_EQ comparisons to correctly mask socket arguments and prevent bypass. Monitor Red Hat's advisory for official profile updates and apply them when available.

Description

CVE-2026-123876 is a vulnerability in the default seccomp profile used by Podman via containers-common on Red Hat Enterprise Linux 10. The deny rules for AF_VSOCK and NETLINK_AUDIT sockets compare arguments using unmasked 64-bit equality, but the Linux kernel truncates these arguments to 32 bits. This discrepancy allows attackers to bypass the deny rules by setting upper bits in the socket arguments. The vulnerability has a medium severity with a CVSS score of 4.4.

Impact

Attackers with local privileges can bypass seccomp deny rules for AF_VSOCK and NETLINK_AUDIT socket types by exploiting the 32-bit truncation of socket arguments, potentially allowing unauthorized socket operations that were intended to be blocked. This results in a low confidentiality and integrity impact, with no impact on availability. The vulnerability requires local access and low privileges, with no user interaction needed.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 17:55 UTC

Technical details

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