Use-after-free in Linux kernel - CVE-2026-80857

Vulnerability identifier: #VU147065

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2026-80857

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

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.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

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

• Use-after-free in Linux kernel fuse
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more