CVE-2026-90349

What the bug is

When mac80211 leaves the link unspecified, mt7996_tx() substitutes the primary link id of the station or vif. That value is IEEE80211_LINK_UNSPECIFIED (0xf) until the first link has been added, and it is then used unchecked to index vif->link_conf[], mvif->mt76.link[] and sta->link[], all of which hold IEEE80211_MLD_MAX_NUM_LINKS (15) entries. Clamp the primary link id to the default link before using it, and use the clamped value for the link_sta fallback as well.

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/mt7996/main.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

mt7996e

Check it on the machine

grep -wE 'CONFIG_MT76_CORE|CONFIG_MT7996E|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 mt7996e

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. The build rule could not be established for 1 release, so nothing is claimed about those.

• bookworm?
• trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, s390x/s390x
• forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x

?

not established - no Makefile entry for the affected file

M

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

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_MT76_CORE, CONFIG_MT7996E, 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 10.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

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
6.18	6.18.52	637bb99cc766
6.18	7.2.6	aff81505a84d
6.18	7.3	4330a0ef9f75