CVE-2026-43343: Linux kernel · usb: gadget: f_subset: Fix unbalanced refcnt in geth_free
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1112.119~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +64
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 to a fixed release listed under Affected software.
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?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?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 to fix the unbalanced reference count issue in the Linux kernel USB gadget function subset. Users should apply the official updates provided by their Linux distribution vendors, such as the Ubuntu security notice USN-8567-1. No additional mitigation actions are indicated beyond applying the official fix.
Description
A vulnerability in the Linux kernel USB gadget function subset (f_subset) was fixed by correcting an unbalanced reference count in the geth_free function. The issue caused geth_alloc() to increment the reference count without a corresponding decrement in geth_free(), preventing proper cleanup and configuration of attributes via configfs after unlinking the function. This flaw could lead to denial of service due to resource mismanagement. The vulnerability affects specific Linux kernel versions and has a medium severity rating with a CVSS score of 5.5. A patch is available to address this issue.
References
- ubuntu.com/security/CVE-2026-43343 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43343 (opens in a new tab)
- git.kernel.org/linus/caa27923aacd8a5869207842f2ab1657c6c0c7bc (opens in a new tab)
- git.kernel.org/stable/c/23e4851ce348a329d974e84e828155dda9f52122 (opens in a new tab)
- git.kernel.org/stable/c/3d436670b47415da042452618fb5d8e317ab095f (opens in a new tab)
- git.kernel.org/stable/c/3f5bfc550a40d7493b1cf09540ed6b412b3b82be (opens in a new tab)
- git.kernel.org/stable/c/75776a055b656873319c3830fed471daef3ceb23 (opens in a new tab)
- git.kernel.org/stable/c/a932b171554714b1bca313b853c7aa9f2930f9aa (opens in a new tab)
- git.kernel.org/stable/c/caa27923aacd8a5869207842f2ab1657c6c0c7bc (opens in a new tab)
- git.kernel.org/stable/c/cc8ec610cd14c093a19371691a7ce1ee5421e829 (opens in a new tab)
- git.kernel.org/stable/c/d7d702407b61e96286a15b6e715572f541a8d41c (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)