SB20261022398 - Use-after-free in Linux kernel futex

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-98788)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to potentially cause a denial of service by triggering access to freed memory in the Linux kernel.

The vulnerability exists due to use-after-free in the private futex hash implementation when resizing the hash and tracking RCU grace periods. A local user can trigger concurrent futex operations during hash resizing to potentially crash the kernel, because futex_ref_drop() can proceed while a reader still holds a pointer to the old hash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5d5dc18b3a9ac011619b7d3af4514bf9e9b6a6af
• https://git.kernel.org/stable/c/f35e3b5784221654f9cdbd6222275a7fa203f6c3