CVE-2026-90382

What the bug is

The MPDU length in the rx descriptor comes from the hardware. In monitor mode with the fcsfail filter enabled, the hardware passes up corrupted frames, and a corrupted frame can report a length larger than the received buffer. The bounds check correctly discards such frames, but its WARN_ON_ONCE wrapper means any over-the-air garbage frame taints the kernel, and panics it on the first such frame when panic_on_warn is set. Drop the WARN and discard the frame silently, matching what commit c2d4c8723dbf ("mt76x2: remove some harmless WARN_ONs in tx status and rx path") did for the neighboring rx and tx status paths. Observed immediately on rx with an MT7612U in fcsfail monitor mode on a busy channel.

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/net/wireless/mediatek/mt76/mt76x02_mac.c

What this is

MEDIATEK MT76 WIRELESS LAN DRIVERMAINTAINERS section matched on drivers/net/wireless/mediatek/mt76/ · linux-wireless@vger.kernel.org · Maintained

Kernel module

mt76x02_lib

Check it on the machine

grep -wE 'CONFIG_MT76_CORE|CONFIG_MT76x02_LIB|CONFIG_WLAN|CONFIG_WLAN_VENDOR_MEDIATEK' /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 mt76x02_lib

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.

• bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
• trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
• 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 switches

CONFIG_MT76_CORE, CONFIG_MT76x02_LIB, CONFIG_WLAN, CONFIG_WLAN_VENDOR_MEDIATEK

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

2026-09-17 (31 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/net

Upstream fixes

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

Introduced	Fixed in	Commit
4.16	5.10.270	61b1f6d92249
4.16	5.15.221	c65bbfc730df
4.16	6.1.188	d55e7aede542
4.16	6.6.157	b6e7958602bd
4.16	6.12.110	2d31e332c13b
4.16	6.18.52	17d6b89e09ea
4.16	7.2.6	6def491fe9c4
4.16	7.3	81497634d9f8

Debian advisories