CVE-2026-43327: Linux kernel · USB: dummy-hcd: Fix locking/synchronization error
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium : upgrade to 7.0.0-1006.6 when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1006.6
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
Upgrade the Ubuntu linux-nvidia package to 7.0.0-1006.6.
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 26.04 LTSlinux-nvidiapkg:deb/ubuntu/linux-nvidia@7.0.0-1006.6?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– |
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 that fixes the locking and synchronization error by adjusting the order of incrementing the callback usage counter in the dummy-hcd driver. Users should apply the official Linux kernel updates provided by their distribution or vendor to remediate this issue. The Ubuntu advisory USN-8567-1 confirms that fixes addressing this and other kernel vulnerabilities have been released. No additional mitigation steps are required beyond applying the official patch.
Description
A synchronization and locking error in the Linux kernel's USB dummy host controller driver (dummy-hcd) was identified and fixed. The flaw allowed a race condition between USB reset handling and driver unbind, causing a crash due to an addressing exception in the usb_gadget_udc_reset() routine. The issue was caused by improper incrementing of a callback usage counter relative to lock acquisition, allowing unsafe clearing of driver references during concurrent operations. This vulnerability affects specific linux-aws kernel versions and has been addressed by a patch that corrects the locking order to prevent the race condition.
References
- ubuntu.com/security/CVE-2026-43327 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43327 (opens in a new tab)
- git.kernel.org/linus/616a63ff495df12863692ab3f9f7b84e3fa7a66d (opens in a new tab)
- git.kernel.org/stable/c/218886b2ef2dea7627d3700ab0abaf4bf9d1161f (opens in a new tab)
- git.kernel.org/stable/c/616a63ff495df12863692ab3f9f7b84e3fa7a66d (opens in a new tab)
- git.kernel.org/stable/c/6350c7dd33ab481ef41c931a238361490c32d15c (opens in a new tab)
- git.kernel.org/stable/c/69ab97a693251d6a6093e630060a3c744fd58524 (opens in a new tab)
- git.kernel.org/stable/c/791966f85b439b261bf19865cf1c07c065ffb4b4 (opens in a new tab)
- git.kernel.org/stable/c/805b1833d6ed6da5086e610578a28e71bb54fbbb (opens in a new tab)
- git.kernel.org/stable/c/cc97fb5969177cccce2e23b31298df220fc7570d (opens in a new tab)
- git.kernel.org/stable/c/efbd9441f1e769a7aae1813d497cec09cbdff031 (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)