CVE-2026-93055

What the bug is

udf_symlink_filler() can enter udf_pc_to_char() with a partial pathComponent header. Validate that enough input remains for a complete pathComponent header before accessing it. Reject malformed symlink data that would otherwise make udf_pc_to_char() perform an out-of-bounds read.

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/udf/symlink.c

What this is

UDF FILESYSTEMMAINTAINERS section matched on fs/udf/ · Maintained

Kernel module

udf

Check it on the machine

grep -w CONFIG_UDF_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 udf

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 as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.

• bookworm, trixie, forky, sid, bookworm · linux-6.12m

m

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

Build switch

CONFIG_UDF_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

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 6.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

fs/udf

Upstream fixes

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

Introduced	Fixed in	Commit
2.6.12	5.10.270	d9f49c8b55de
2.6.12	5.15.221	48b2a74317e1
2.6.12	6.1.188	f44f5f795f1a
2.6.12	6.6.157	57371e743398
2.6.12	6.12.110	ee264227b656
2.6.12	6.18.52	8da8fd3df9fc
2.6.12	7.2.6	b21cb958292e
2.6.12	7.3	d23eb7380d15

Debian advisories