SB20260816228 - Missing Release of Resource after Effective Lifetime in Linux kernel fs

Description

This security bulletin contains information about 1 vulnerability.

1) Missing Release of Resource after Effective Lifetime (CVE-ID: CVE-2026-74483)

CWE-ID: CWE-772 - Missing Release of Resource after Effective Lifetime

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper resource shutdown in binfmt_misc superblock handling when mounting binfmt_misc in a user namespace and triggering mount failure. A remote attacker can repeatedly trigger failed mounts to cause a denial of service.

Exploitation is possible by an unprivileged caller under a tight memory cgroup, which can force mount failures and leak one user namespace per attempt.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/87a4eb9bbb3497f749bbac612af22ddaa62d7b0d
• https://git.kernel.org/stable/c/b8206f516fe7cbe785cf44bf09c17c438d7c3cad