Out-of-bounds read in Linux kernel - CVE-2026-74689

Vulnerability details

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in vcc_setsockopt() when processing crafted setsockopt calls. A local user can supply a mismatched level or a shortened optlen value to trigger an out-of-bounds read and disclose sensitive information.

The issue can also be triggered if a cgroup BPF setsockopt filter shrinks optlen after entry.

Affected software

How to mitigate CVE-2026-74689

External References

• https://git.kernel.org/stable/c/2c5988c7349c0b64a7e0441bfc6e1dca54f7116a
• https://git.kernel.org/stable/c/35f258fee9ed358c6d0f57f91c30bf029c3724af
• https://git.kernel.org/stable/c/6eb6af88710977eb529b558a07294874d8c40c4d
• https://git.kernel.org/stable/c/9f77c1ab382188f5b51982fab6d913443b6dc59f
• https://git.kernel.org/stable/c/b3bcd5d65ac03c15787b2a5b36c718e26a689336
• https://git.kernel.org/stable/c/d0c80dbb970439bd2eeb0e5effff8c16a5f4e1e3

Related Security Bulletins

• Out-of-bounds read in Linux kernel atm
• Debian update for linux