CVE-2026-43429: Linux kernel · USB: usbtmc: Use usb_bulk_msg_killable() with user-specified timeouts
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 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.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions to resolve this issue. The fix replaces usb_bulk_msg() calls with usb_bulk_msg_killable() in the usbtmc driver to respect user-specified timeouts and prevent indefinite kernel thread hangs. Users should update to patched kernel versions as provided by their Linux distribution vendors.
Description
A vulnerability in the Linux kernel's usbtmc driver allowed user-specified timeouts in ioctl commands to be used in usb_bulk_msg() calls, which use unkillable waits. This could cause a kernel thread to hang indefinitely. The issue was fixed by switching to usb_bulk_msg_killable() to respect user-specified timeouts and avoid indefinite hangs. The vulnerability affects specific Linux kernel versions listed and has a medium severity with a CVSS score of 5.5. A patch is available to address this issue.
References
- ubuntu.com/security/CVE-2026-43429 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43429 (opens in a new tab)
- git.kernel.org/linus/7784caa413a89487dd14dd5c41db8753483b2acb (opens in a new tab)
- git.kernel.org/stable/c/0535f84cb94c9d8bcba0a2a5b3fac81b7d97235d (opens in a new tab)
- git.kernel.org/stable/c/39bd4097292fd8564cf2cfba9356f8ab11e38d12 (opens in a new tab)
- git.kernel.org/stable/c/6cb7dc91f057dd8ce44f6caa2995d8e22784ed0a (opens in a new tab)
- git.kernel.org/stable/c/72c0a063489be183cfb99e7050aaef503bdb6449 (opens in a new tab)
- git.kernel.org/stable/c/7784caa413a89487dd14dd5c41db8753483b2acb (opens in a new tab)
- git.kernel.org/stable/c/7fa72c369c23c27d1f64883c1e276af950557fb1 (opens in a new tab)
- git.kernel.org/stable/c/d4f1c45bdff3f393f9ab7e76795901c442b9eb76 (opens in a new tab)
- git.kernel.org/stable/c/e14a0dcdf468c3ad616bb06696c7c64c36e736d8 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)