CVE-2026-98699

What the bug is

mesh_fast_tx_cache() stores raw mesh_path pointers. Path deletion flushes the cache and then frees the path with kfree_rcu(), but a lookup that already holds the path can insert a new cache entry after the flush. The cache then points at freed memory. Set MESH_PATH_DELETED before flushing, and skip inserting a cache entry if the path or MPP path is already deleted. Check this under the cache walk lock so it is ordered with the flush. Use WRITE_ONCE() for the deletion flag updates because the cache check reads flags without taking state_lock.

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.

net/mac80211/mesh_pathtbl.c

What this is

MAC80211MAINTAINERS section matched on net/mac80211/ · linux-wireless@vger.kernel.org · Maintained

Kernel module

mac80211

Check it on the machine

grep -wE 'CONFIG_MAC80211|CONFIG_MAC80211_MESH' /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 mac80211

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

M

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

Build switches

CONFIG_MAC80211, CONFIG_MAC80211_MESH

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

2026-10-18 (today)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

not scored

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

net/mac80211

Upstream fixes

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

Introduced	Fixed in	Commit
6.4	6.12.113	0117f1aa1894
6.4	6.18.56	128e800a4127
6.4	7.2.10	93da3ec938bf
6.4	7.3	ee3aadc43ea6