CVE-2026-74673

What the bug is

In evdev_pass_values(), the input_event structure is allocated on the kernel stack and populated field-by-field. However, it is never fully initialized. On architectures where struct input_event contains explicit or implicit padding (such as the 32-bit __pad field on SPARC64), these padding bytes are left uninitialized. When this event structure is subsequently passed to the client buffer and later copied to userspace, the uninitialized padding bytes leak kernel stack memory, potentially exposing sensitive information. Similar issues exist in __evdev_queue_syn_dropped and __pass_event. Fix this by explicitly zeroing the entire event structure with memset() before populating its fields. This ensures all padding bytes are cleared before the data crosses the security boundary.

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/input/evdev.c

What this is

INPUT (KEYBOARD, MOUSE, JOYSTICK, TOUCHSCREEN) DRIVERSMAINTAINERS section matched on drivers/input/ · linux-input@vger.kernel.org · Maintained

Kernel module

evdev

Check it on the machine

grep -wE 'CONFIG_INPUT|CONFIG_INPUT_EVDEV' /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 evdev

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 switches

CONFIG_INPUT, CONFIG_INPUT_EVDEV

Reads as

all on means the file is compiled; any one off means it is not.

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

2026-08-22 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 6.8% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/input

Upstream fixes

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

Introduced	Fixed in	Commit
2.6.24	5.10.265	d2e3839419ac
2.6.24	5.15.216	c6d5fa46c1ee
2.6.24	6.1.183	e748811d9b80
2.6.24	6.6.152	06a286b32023
2.6.24	6.12.104	7d17e9454a9a
2.6.24	6.18.45	bd3c4108a56d
2.6.24	7.1.9	7e55ca1080f0
2.6.24	7.2	90f305f2c7a3

Debian advisories