Missing length check in Linux kernel mac80211 deauth handling
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 4.2 is affected in its mac80211 Wi-Fi stack. The function ieee80211_rx_mgmt_deauth() reads the deauthentication reason code before checking that the received frame contains that field, so it can read past the end of a short frame.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: validate deauth frame length before reason access ieee80211_rx_mgmt_deauth() reads the deauth reason code before checking that the fixed field is actually present in the received frame. Validate the deauth frame length first and only then read the reason code.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53 or 7.2, matching your branch. Red Hat rates this Moderate. Red Hat Enterprise Linux 6 has no fix planned, and Red Hat Enterprise Linux 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5 have no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-23 Threatist record created from CVE-2026-98891
- 2026-10-23 Alias added: GHSA-gf5m-xgmc-5rr4
- 2026-10-26 Fix available: Linux/Linux@0 · CNA
- 2026-10-26 Affected versions changed · Red Hat
- 2026-10-26 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/51092dc769f021e9634474e1bd5a561da477fbdb
- https://git.kernel.org/stable/c/a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e
- https://git.kernel.org/stable/c/80d1a110e9096b5bf41497f6b151154084862385
- https://git.kernel.org/stable/c/a78689e2beed200d4590318612c74ae25c9408cf
- https://git.kernel.org/stable/c/7a5ef1fd654d0e90d59aa32c881789c8bcc4125a
- https://git.kernel.org/stable/c/9df64ad43e1f2c036667bba2bf385e9d7b3af564
- https://git.kernel.org/stable/c/4a360c6e18dfa9d70006c7247a6a8cc8dfe0d60f
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Sources
- CVE-2026-98891 · CVE Program
- CVE-2026-98891 · NVD
- FIRST EPSS
- GHSA-gf5m-xgmc-5rr4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98891 · 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