CVE-2026-89892

What the bug is

The audio-only path registers extensions while probing the primary device. For a dual-TS board, this happens before dev_next is created. The duplicate device inherits is_audio_only and is then independently inserted into em28xx_devlist. The list is intended to contain only primary devices: extension operations reach the secondary device through dev_next. The independently linked secondary can be freed during disconnect while its list node remains reachable, resulting in a use-after-free. Defer audio-only extension registration to the module-request work item. It runs only after probing has completed construction of the optional secondary device, so only the primary is registered and extension callbacks reach the secondary through dev_next.

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.

drivers/media/usb/em28xx/em28xx-cards.c

What this is

EM28XX VIDEO4LINUX DRIVERMAINTAINERS section matched on drivers/media/usb/em28xx/ · linux-media@vger.kernel.org · Maintained

Kernel module

em28xx

Check it on the machine

grep -w CONFIG_VIDEO_EM28XX /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 em28xx

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, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switch

CONFIG_VIDEO_EM28XX

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

2026-09-16 (33 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/media

Upstream fixes

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

Introduced	Fixed in	Commit
4.17	5.10.270	0da1e627f4fc
4.17	5.15.221	f8d7e77d9c62
4.17	6.1.188	1abe9524dec0
4.17	6.6.157	4e11c45dfdc7
4.17	6.12.110	d06067ee3262
4.17	6.18.51	f9322ac9f862
4.17	7.2.5	4666197ca4f7
4.17	7.3	95f76f51937f

Debian advisories