CVE-2026-68402

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: bound element ID read when checking non-inheritance

cfg80211_is_element_inherited() reads the first data octet of the candidate element (id = elem->data[0]) to look it up in an extension non-inheritance list. It does so after testing elem->id, but without verifying that the element actually has a data octet. A zero-length extension element (WLAN_EID_EXTENSION with length 0) therefore makes it read one octet past the end of the element.

_ieee802_11_parse_elems_full() runs this check for every element of a frame once a non-inheritance context exists – e.g. while parsing a per-STA profile of a Multi-Link element in a (re)association response, or a non-transmitted BSS profile – so a crafted frame from an AP can trigger a one-octet slab-out-of-bounds read during element parsing:

BUG: KASAN: slab-out-of-bounds in cfg80211_is_element_inherited Read of size 1 … in net/wireless/scan.c

Return early (treat the element as inherited) when an extension element carries no data, mirroring the existing handling of empty ID lists.

The bug was found by fuzzing ieee802_11_parse_elems_full() under KASAN.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS

Affected packages:

linux @ 4.19.0 (+7 more)

Live-patch status from KernelCare for each operating system.