Cloudanix VulnDB

CVE-2026-98423

None

CVSS

—

EPSS

0.2%

Published

Oct 14, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A timing flaw in wireless testing tools inside the operating system can produce unexpected warnings during simulated network operations.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Race condition in mac80211_hwsim permits frames from wmediumd to reach mac80211 after the radio has stopped, triggering WARN_ON(!local->started).

Why it matters to the business

Kernel warnings or instability limited to wireless simulation test environments; low exploitation likelihood and no ransomware association reduce urgency despite recent publication.

How an attack unfolds

An attacker with local access times radio stop operations against wmediumd frame delivery to hit the unprotected window and generate the assertion warning.

How to fix it

Apply the upstream kernel commit that expands the mutex around the started check and adds synchronization on radio stop; rebuild and deploy the patched kernel.

How to confirm the fix worked

Confirm the mutex expansion and stop synchronization are present in the mac80211_hwsim source; verify absence of the WARN_ON after stress-testing frame delivery during stop sequences.

Typical attack path

  1. Gain local access to a system using mac80211_hwsim
  2. Monitor or influence radio start/stop state
  3. Deliver frames via wmediumd after stop check but before delivery
  4. Trigger WARN_ON in mac80211

How to detect it

Search kernel logs and dmesg for WARN_ON messages referencing local->started in conjunction with mac80211_hwsim or wmediumd activity; review recent radio stop events.

  • WARN_ON(!local->started)
  • mac80211_hwsim
  • wmediumd frame delivery during stop

What your security team should do

  • Prioritize patching systems that run mac80211_hwsim for development or testing
  • Monitor kernel logs for the specific WARN_ON pattern
  • Restrict mac80211_hwsim usage to isolated lab environments until updated

The record

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211_hwsim: don't hand frames to mac80211 while stopping The code checks ->started for frames coming from wmediumd, but the radio can be stopped after the check and before frame delivery, causing mac80211 to hit the WARN_ON(!local->started). Expand the mutex for this case and synchronise against it when the radio is stopped to avoid being able to hit the warning with hwsim. Drop the error print that would've complicated the error path, it only triggers for allocation failures (already noisy) and malformed frames anyway.

Affected packages

Ecosystem Package Introduced Fixed