CVE-2026-43340
MediumIn the Linux kernel, the following vulnerability has been resolved: comedi: Reinit dev->spinlock between attachments to low-level drivers `struct comedi_device` is the main controlling structure for a COMEDI device created by the COMEDI subsystem. It contains a member `spinlock` containing a spin-lock that is initialized by the COMEDI subsystem, but is reserved for use by a low-level driver attached to the COMEDI device (at least since commit 25436dc9d84f ("Staging: comedi: remove RT code")). Some COMEDI devices (those created on initialization of the COMEDI subsystem when the "comedi.comedi_num_legacy_minors" parameter is non-zero) can be attached to different low-level drivers over their lifetime using the `COMEDI_DEVCONFIG` ioctl command. This can result in inconsistent lock states being reported when there is a mismatch in the spin-lock locking levels used by each low-level driver to which the COMEDI device has been attached. Fix it by reinitializing `dev->spinlock` before calling the low-level driver's `attach` function pointer if `CONFIG_LOCKDEP` is enabled.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
2.6.29
and later are affected. Fixed in
5.10.253,
5.15.203,
6.1.168,
6.6.134,
6.12.81,
6.18.22,
6.19.12,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-43340 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/2b1f49e4fdff3ef0f8e9158bbb5b149e06287560
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PatchKernel patch commithttps://git.kernel.org/stable/c/3181c34b415c5464be9d34bff3e43ef63b747039
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PatchKernel patch commithttps://git.kernel.org/stable/c/430291d8f3884f57ae0057049b0ca291453e29e1
Frequently asked questions
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What is CVE-2026-43340?
CVE-2026-43340 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 2.6.29 onward and has been patched in 5.10.253, 5.15.203, 6.1.168 and others. CVE-2026-43340 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-43340?
CVE-2026-43340 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-43340?
Yes — CVE-2026-43340 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.168 and others. If you are running Linux kernel 2.6.29 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-43340 actively exploited?
No — CVE-2026-43340 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.