SB20260625220 - Use-after-free in Linux kernel futex hash allocation logic

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-52973)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in futex hash allocation logic when creating a CLONE_VM clone that shares the memory map outside strict CLONE_THREAD semantics. A local user can create a crafted clone scenario to cause a denial of service.

The issue arises when the memory map is shared in ways other than pthread-style threading, which can leave a biased per-cpu futex reference pointing to freed memory.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1dcd36420af2da5bd59306dba9caf78e3d248b1d
• https://git.kernel.org/stable/c/974ac49a9a068b0591a59f65c63eb06579a13091
• https://git.kernel.org/stable/c/ee9dce44362b2d8132c32964656ab6dff7dfbc6a