CVE-2026-53167

What the bug is

FUSE_NOTIFY_RETRIEVE must be limited to uptodate folios; !uptodate folios can contain uninitialized data. Since FUSE_NOTIFY_RETRIEVE is intended to only return data that is already in the page cache and not wait for data from the FUSE daemon, treat !uptodate folios as if they weren't present. This only has security impact on systems that don't enable automatic zero-initialization of all page allocations via CONFIG_INIT_ON_ALLOC_DEFAULT_ON or init_on_alloc=1.

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

2026-06-25 (4 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.13%, higher than 2.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

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
2.6.36	5.10.260	feafe8ccb158
2.6.36	5.15.211	651801d75ad0
2.6.36	6.1.177	4e14f29473ed
2.6.36	6.6.144	8bef2f840b43
2.6.36	6.12.95	68a9282d5ea5
2.6.36	6.18.36	56763afa0134
2.6.36	7.0.13	1fb8735a3a4d
2.6.36	7.1	4e3d1b2c48ca

Debian advisories