VulnerabilityPublished 23 Oct 2026

CVE-2026-98891: Linux kernel · wifi: mac80211: validate deauth frame length before reason access

Source GCVE Database

Authoritative record:CVE-2026-98891

Not known to be exploited · fixed in a78689e2beed200d4590318612c74ae25c9408cf : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a78689e2beed200d4590318612c74ae25c9408cf, a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e, 51092dc769f021e9634474e1bd5a561da477fbdb +4

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-gf5m-xgmc-5rr4

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < a78689e2beed200d4590318612c74ae25c9408cf	Fixed in a78689e2beed200d4590318612c74ae25c9408cf
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e	Fixed in a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < 51092dc769f021e9634474e1bd5a561da477fbdb	Fixed in 51092dc769f021e9634474e1bd5a561da477fbdb
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < 80d1a110e9096b5bf41497f6b151154084862385	Fixed in 80d1a110e9096b5bf41497f6b151154084862385
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < 9df64ad43e1f2c036667bba2bf385e9d7b3af564	Fixed in 9df64ad43e1f2c036667bba2bf385e9d7b3af564
LinuxLinux	Affected ≥ c9c99f8938e41b878802d5d8481d6f7a212515b0, < 7a5ef1fd654d0e90d59aa32c881789c8bcc4125a	Fixed in 7a5ef1fd654d0e90d59aa32c881789c8bcc4125a

AI-suggested

A fix has been implemented in the Linux kernel to validate the deauthentication frame length before accessing the reason code. Users should apply the official kernel updates that include this patch. Since no vendor advisory or patch links are provided, check the Linux kernel mailing lists or official repositories for the relevant patch and update accordingly.

Description

A vulnerability in the Linux kernel's mac80211 WiFi component was resolved by validating the deauthentication frame length before accessing the reason code. The function ieee80211_rx_mgmt_deauth() previously read the deauthentication reason code without first confirming that the frame contained the expected fixed field, potentially leading to improper handling of malformed frames.

Impact

Improper validation of the deauthentication frame length could lead to out-of-bounds memory reads within the kernel's WiFi management code. This may cause kernel instability or potentially enable denial of service conditions. No confirmed exploits or further impact details are provided.

Summary

The Linux kernel's mac80211 subsystem had a vulnerability where the ieee80211_rx_mgmt_deauth() function accessed the deauthentication reason code before verifying that the deauthentication frame was of sufficient length to contain this field. This could result in reading beyond the frame boundary. The issue was fixed by adding validation of the deauthentication frame length prior to accessing the reason code.

References

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