SB20260727315 - NULL pointer dereference in Linux kernel fuse

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-64263)

CWE-ID: CWE-476 - NULL Pointer Dereference

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 null pointer dereference in the fuse-uring request handling code when processing cancellation of available entries moved to the ent_in_userspace list. A local user can trigger cancellation of a crafted entry state to cause a denial of service.

The crash occurs because the first entry on the ent_in_userspace list may be dereferenced even when no fuse request is attached.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc
• https://git.kernel.org/stable/c/50f3e03db823cabc41fe35c27d77c2bdb112baad
• https://git.kernel.org/stable/c/e8afc85acdf329361b2d8df2ad9b52364686235f