Executive brief
A vulnerability exists in the software responsible for managing Wi-Fi access points and client connections on many Linux-based systems. An attacker within wireless range can send a specially crafted Wi-Fi 7 management frame to crash the service, resulting in a denial of service. This attack does not require any passwords or prior authentication, potentially disrupting wireless connectivity for all users on the affected network.
Technical details
An off-by-one error exists in the parsing of Multi-Link Elements (MLE) within IEEE 802.11be (Wi-Fi 7) association requests. In hostapd_process_ml_assoc_req(), the link_id field is masked to a value between 0 and 15, but the internal links array only contains 15 entries (indices 0-14). A crafted frame with a link_id of 15 triggers an out-of-bounds write. This occurs during the association phase before the 4-way handshake, meaning no authentication or network credentials are required. The primary impact is a crash of the hostapd or wpa_supplicant process (Denial of Service). The issue is fixed in version 2.12 and via upstream patches in the 2026-1 security release.
Affected products
- w1.fi hostapd v2.11 and newer development snapshots before v2.12
- w1.fi wpa_supplicant v2.11 and newer development snapshots before v2.12
Timeline
- 2026-05-14: other: Reported to upstream
- 2026-06-05: advisory: Upstream security advisory published
- 2026-06-30: disclosed: Public disclosure and CVE assignment
References
- https://git.w1.fi/cgit/hostap/commit/?id=46dd5a4ffc9bcf44cf8fc45120b3e1e5ec922187
- https://git.w1.fi/cgit/hostap/commit/?id=aa9d345887389a251c63a3781d2ad2940d079193
- https://w1.fi/security/2026-1/
- https://w1.fi/security/2026-1/missing-ml-parsing-validation.txt
- https://www.openwall.com/lists/oss-security/2026/06/30/1