SB2026090596 - Use-after-free in Linux kernel fuse

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-80857)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a use-after-free.

The vulnerability exists due to a failure to wait for request completion in the FUSE request_wait_answer() function when the abort_on_kill path is triggered while fuse_dev_do_write() is concurrently processing the same request. A local user can trigger the abort_on_kill path for a concurrently processed request to cause a use-after-free.

Exploitation requires the request to be marked FR_LOCKED while its arguments are freed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/64b0b5cacbd2fea88001464cb712c9dfc795b26e
• https://git.kernel.org/stable/c/715cb86e33cda43f5224cdc3fd5610c0b6a46f7a