CVE-2026-64255: Linux kernel · wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 7.0.0-31.31~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-1012.12 +7
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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().
References
- ubuntu.com/security/CVE-2026-64255 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64255 (opens in a new tab)
- git.kernel.org/linus/f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 (opens in a new tab)
- git.kernel.org/stable/c/1de92789ce31e46fa7e7d8e89c90b19cdb1c103b (opens in a new tab)
- git.kernel.org/stable/c/f056fc2b927448d37eca6b6cacc3d1b0f67b20d2 (opens in a new tab)
- git.kernel.org/stable/c/fe7f339f63c9dc4ca546ed7ac38ba4bb3a99dcfc (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)