CVE-2026-80857

What the bug is

The abort_on_kill path in request_wait_answer() calls fuse_abort_conn() and returns without waiting for FR_FINISHED. If fuse_dev_do_write() is concurrently processing the same request (FR_LOCKED set), the caller frees req->args while it is still being accessed, causing a use-after-free. Fix this by jumping to the existing wait_event(FR_FINISHED) instead of returning early. The wait will not hang because fuse_abort_conn() ensures all requests are ended.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

fs/fuse/dev.c

What this is

FUSE FILESYSTEM [CORE]MAINTAINERS section matched on fs/fuse/ · fuse-devel@lists.linux.dev · Supported

Kernel module

fuse

Check it on the machine

grep -w CONFIG_FUSE_FS /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w fuse

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this code. Every release below compiles the affected file into the kernels it ships.

• bookwormm
• trixie, forky, sidy

m

a loadable module on every flavour - check lsmod, can be blacklisted

y

built into the kernel image on every flavour - only a patch removes it

Build switch

CONFIG_FUSE_FS

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.15%, higher than 4.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

fs/fuse

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.18.25	6.18.50	a8bbb2a60513
7.1	7.2.3	715cb86e33cd
7.1	7.3	64b0b5cacbd2
7.0.2	0	0