---
cve: "CVE-2026-64255"
severity: "HIGH"
cvss: 8.8
epss: "23%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-24 16:16:55"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T16:20:28+02:00"
---

# CVE-2026-64255

> 8.8 HIGH

## Beschreibung

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-Vektor

```
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Benachbart | warn |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.38
- Kernel ≥ 7.1.3

## Referenzen

- <https://git.kernel.org/stable/c/1de92789ce31e46fa7e7d8e89c90b19cdb1c103b>
- <https://git.kernel.org/stable/c/fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc>
- <https://git.kernel.org/stable/c/f056fc2b927448d37eca6b6cacc3d1b0f67b20d2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-64255) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_