CVE-2026-64223: Linux Kernel

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements against the number of link-map entries indicated by link_map_presence. ieee80211_parse_neg_ttlm() must consume the same layout. The parser advanced its cursor for every TID, including TIDs whose presence bit is clear and therefore have no map bytes in the element. A sparse map can then make a later present TID read past the validated element. The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by valid_links before being applied to driver state, so a peer cannot turn the read into a policy change. Under KUnit + KASAN with an exact-sized element allocation the OOB read is reported as a slab-out-of-bounds; whether the same trigger fires under the production RX path depends on surrounding allocator state. Advance the cursor only when the current TID has a map present.

Affected products

• Linux Linux Kernel: from 6.9, before 6.12.92 (fixed in 6.12.92); from 6.13, before 6.18.34 (fixed in 6.18.34); from 6.19, before 7.0.11 (fixed in 7.0.11); version 7.1 only

Published 2026-07-24. Last modified 2026-08-12.