CVE-2026-64255

wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers

HIGH
8.8
CVSS Score
Published: July 24, 2026 at 03:31 PM UTC
Updated: October 19, 2026 at 09:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.19 ≤ v < 7.1.36.4 ≤ v < 6.18.386.49aa3856d9b6f3f8bf085b5bbb5f3703578bf452b
Vendor states this is fixed in 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b (fixed)
Vendor states this is fixed in f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 (fixed)
Vendor states this is fixed in fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc (fixed)
Vendor states this is fixed in 6.18.38 (unaffected)
Vendor states this is fixed in 6.4 (unaffected)
Vendor states this is fixed in 7.1.3 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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