CVE-2026-64223wifi: mac80211: consume only present negotiated TTLM maps

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.

CVSS

8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Weakness (CWE)

CWE-125

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Modified

Record last updated

Oct 19, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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