wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 10 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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().
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.18.38, 7.1.3, 7.2
Red Hat 2 advisories
- RHSA-2026:67150 Released 2026-09-14 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.47.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.47.1.el9_8, kernel-64k-devel-5.14.0-687.47.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.47.1.el9_8, kernel-64k-5.14.0-687.47.1.el9_8, kernel-64k-core-5.14.0-687.47.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.47.1.el9_8, libperf-5.14.0-687.47.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.47.1.el9_8, kernel-rt-64k-5.14.0-687.47.1.el9_8, kernel-rt-64k-core-5.14.0-687.47.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.47.1.el9_8, kernel-rt-core-5.14.0-687.47.1.el9_8, kernel-rt-debug-5.14.0-687.47.1.el9_8 +9
- RHSA-2026:65334 Released 2026-09-08 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.53.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.53.1.el10_2, kernel-64k-devel-6.12.0-211.53.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.53.1.el10_2, kernel-64k-6.12.0-211.53.1.el10_2, kernel-64k-core-6.12.0-211.53.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.53.1.el10_2, libperf-6.12.0-211.53.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.53.1.el10_2, kernel-rt-64k-6.12.0-211.53.1.el10_2, kernel-rt-64k-core-6.12.0-211.53.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.53.1.el10_2, kernel-rt-core-6.12.0-211.53.1.el10_2, kernel-rt-debug-6.12.0-211.53.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:67150 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:67150 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:67150 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:67150 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:67150 |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64255
- 2026-10-03 Alias added: GHSA-3prq-7cqf-r4ww
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
- 2026-10-25 Priority changed: LOW → MEDIUM
- 2026-10-31 CVSS score changed · Red Hat
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-64255 · CVE Program
- CVE-2026-64255 · NVD
- FIRST EPSS
- GHSA-3prq-7cqf-r4ww · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64255 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences