CVE-2026-64255: Linux Kernel

High severity, CVSS 8.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers Three BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a station ID without checking that sta_mask is non-zero. When sta_mask is zero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing an out-of-bounds access on fw_id_to_link_sta[]. Add WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call, consistent with the existing check in iwl_mld_ampdu_rx_start().

Affected products

• Linux Linux Kernel: from 6.4, before 6.18.38 (fixed in 6.18.38); from 6.19, before 7.1.3 (fixed in 7.1.3)

Published 2026-07-24. Last modified 2026-08-17.