SB2026072736 - Use-after-free in Linux kernel handshake

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-64523)

CWE-ID: CWE-416 - Use After Free

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 local user to cause a denial of service.

The vulnerability exists due to a use-after-free in handshake_req_submit() and the net/handshake request handling code when processing a pending handshake request while the associated socket file is released concurrently. A local user can trigger a race involving socket teardown and handshake submission to cause a denial of service.

The issue arises because a socket reference alone does not keep the backing struct socket alive, and a concurrent cancellation or completion path can race request cleanup.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/09dba37eee70d0596e26645015f1aa95a9848e9d
• https://git.kernel.org/stable/c/16eaba5aa89c04eea125905bb8f988c1897f4f29
• https://git.kernel.org/stable/c/685b10dd0e32c7782cead16c8cf055c609678583