Review reviewHigh

CVE-2026-64255

Linux

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().

CVSS: 8.8
EPSS: -
CISA KEV: Not listed
Published: 2026.07.25

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 8.8

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b < 1de92789ce31e46fa7e7d8e89c90b19cdb1c103b, >= 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b < fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc, >= 9aa3856d9b6f3f8bf085b5bbb5f3703578bf452b < f056fc2b927448d37eca6b6cacc3d1b0f67b20d2, >= 6.4
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: Not available