CVE-2026-43255: Linux kernel · wifi: libertas: fix WARNING in usb_tx_block
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fc188b44547dea4e7350833171982a6312befde9 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 15:50 UTC
Rated Low by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- 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, 2026-11-06.
- Patch
- Available – fixed in fc188b44547dea4e7350833171982a6312befde9, d66676e6ca96bf8680f869a9bd6573b26c634622, b82073564373e68c6ae3a96039fae14cd002a496 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 6 May 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 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in multiple Linux kernel versions as indicated by the fixed commit hashes. Users should update their Linux kernel to a version that includes these fixes to resolve the issue. No additional mitigation steps are required beyond applying the official patch.
Description
A vulnerability in the Linux kernel's wifi libertas driver caused a warning due to submitting a USB request block (URB) while it was still active. This occurred because the function usb_tx_block() did not ensure that a previous transmission had completed before submitting a new URB. The issue was fixed by enforcing serialization with usb_kill_urb() to ensure the URB is idle before reuse.
References
- git.kernel.org/stable/c/498525d8358d6d20918787e59736d5b6a021e9fd (opens in a new tab)
- git.kernel.org/stable/c/2902a9b4415a6bafc9b1e5dd360f065d757a0bb7 (opens in a new tab)
- git.kernel.org/stable/c/948a39c95d0f8d73722910f8cdb7b6e3e9206232 (opens in a new tab)
- git.kernel.org/stable/c/5bfb25495e391a1be0db94b15715174fa06b93a1 (opens in a new tab)
- git.kernel.org/stable/c/b82073564373e68c6ae3a96039fae14cd002a496 (opens in a new tab)
- git.kernel.org/stable/c/3308c7504e093b22e91a4468470309cee2e26b83 (opens in a new tab)
- git.kernel.org/stable/c/fc188b44547dea4e7350833171982a6312befde9 (opens in a new tab)
- git.kernel.org/stable/c/d66676e6ca96bf8680f869a9bd6573b26c634622 (opens in a new tab)