wifi: mac80211: disconnect on CSA to channel 0

Answer in brief

CVE-2026-90344 records a Unknown severity vulnerability in wifi: mac80211: disconnect on CSA to channel 0. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=21c3f8f95554feff9bed15703e89adbe582e0383 <099aadb2012d7490bc584cc5075ef11cbc33f2c3 \|\| >=21c3f8f95554feff9bed15703e89adbe582e0383 <e7bc5ab93acd1c3f54feeb9fa19ead3530168090 \|\| >=21c3f8f95554feff9bed15703e89adbe582e0383 <eef374088450bb91626e133c7172b8a0e969a522 \|\| >=21c3f8f95554feff9bed15703e89adbe582e0383 <cf57f0a674cc3e3cda1a789359cc1238b61b9d7d	099aadb2012d7490bc584cc5075ef11cbc33f2c3, e7bc5ab93acd1c3f54feeb9fa19ead3530168090, eef374088450bb91626e133c7172b8a0e969a522, cf57f0a674cc3e3cda1a789359cc1238b61b9d7d
Linux/Linuxgeneric	6.9	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 099aadb2012d7490bc584cc5075ef11cbc33f2c3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: disconnect on CSA to channel 0 The refactor for the CSA parsing erroneously equates channel zero and no information present, leading it to ignore a CSA on an AP that advertises a switch to that (invalid) channel. This leads to not disconnecting, which we should. For Intel devices, this can lead to a firmware crash. Fix this by using an int type for the channel number as well as the opclass, and using a (negative) value that cannot be encoded in the element to indicate it's not present.

Quoted source text, attributed separately from HOL analysis.