VulnerabilityPublished 3 Apr 2026Updated 5 Nov 2026

CVE-2026-31394: Linux kernel · mac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in 672e5229e1ecfc2a3509b53adcb914d8b024a853 : update Linux kernel when convenient.

Data as of 5 Nov 2026, 22:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-05.

Patch

Available – fixed in 672e5229e1ecfc2a3509b53adcb914d8b024a853, 65c25b588994dd422fea73fa322de56e1ae4a33b, 5a86d4e920d9783a198e39cf53f0e410fba5fbd6 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 5 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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.

What to do

Upgrade Linux kernel to 672e5229e1ecfc2a3509b53adcb914d8b024a853, 65c25b588994dd422fea73fa322de56e1ae4a33b, 5a86d4e920d9783a198e39cf53f0e410fba5fbd6 or 3c6629e859a2211a1fbb4868f915413f80001ca5.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b27512368591fc959768df1f7dacf2a96b1bd036, < 672e5229e1ecfc2a3509b53adcb914d8b024a853	Fixed in 672e5229e1ecfc2a3509b53adcb914d8b024a853
LinuxLinux	Affected ≥ b27512368591fc959768df1f7dacf2a96b1bd036, < 65c25b588994dd422fea73fa322de56e1ae4a33b	Fixed in 65c25b588994dd422fea73fa322de56e1ae4a33b
LinuxLinux	Affected ≥ b27512368591fc959768df1f7dacf2a96b1bd036, < 5a86d4e920d9783a198e39cf53f0e410fba5fbd6	Fixed in 5a86d4e920d9783a198e39cf53f0e410fba5fbd6
LinuxLinux	Affected ≥ b27512368591fc959768df1f7dacf2a96b1bd036, < 3c6629e859a2211a1fbb4868f915413f80001ca5	Fixed in 3c6629e859a2211a1fbb4868f915413f80001ca5
LinuxLinux	Affected =6.11	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix crash in ieee80211_chan_bw_change for AP_VLAN stations ieee80211_chan_bw_change() iterates all stations and accesses link->reserved.oper via sta->sdata->link[link_id]. For stations on AP_VLAN interfaces (e.g. 4addr WDS clients), sta->sdata points to the VLAN sdata, whose link never participates in chanctx reservations. This leaves link->reserved.oper zero-initialized with chan == NULL, causing a NULL pointer dereference in __ieee80211_sta_cap_rx_bw() when accessing chandef->chan->band during CSA. Resolve the VLAN sdata to its parent AP sdata using get_bss_sdata() before accessing link data. [also change sta->sdata in ARRAY_SIZE even if it doesn't matter]

References

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