CVE-2026-64223: In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size_o

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.

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.39%, higher than 32% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

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Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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