Skip to main content
VulnerabilityPublished Updated

CVE-2026-31486: Linux kernel · hwmon: (pmbus/core) Protect regulator operations with mutex

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.1 High · fixed in b26849cffaa7c43355b82e9bef3725e786973a1a : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
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.
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, 2026-10-16.

Patch
Available – fixed in b26849cffaa7c43355b82e9bef3725e786973a1a, acf04e2863132f6d9222f71f3a76fb9782cbe061, 754bd2b4a084b90b5e7b630e1f423061a9b9b761 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 22 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, < b26849cffaa7c43355b82e9bef3725e786973a1a
Fixed in
  • b26849cffaa7c43355b82e9bef3725e786973a1a
LinuxLinuxAffected
  • ≥ ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, < acf04e2863132f6d9222f71f3a76fb9782cbe061
Fixed in
  • acf04e2863132f6d9222f71f3a76fb9782cbe061
LinuxLinuxAffected
  • ≥ ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, < 754bd2b4a084b90b5e7b630e1f423061a9b9b761
Fixed in
  • 754bd2b4a084b90b5e7b630e1f423061a9b9b761
LinuxLinuxAffected
  • ≥ ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, < 4e9d723d9f198b86f6882a84c501ba1f39e8d055
Fixed in
  • 4e9d723d9f198b86f6882a84c501ba1f39e8d055
LinuxLinuxAffected
  • ≥ ddbb4db4ced1ba784fcd3500179a7291b6c5d7b7, < 2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07
Fixed in
  • 2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07
LinuxLinuxAffected
  • =3.19
Fixed in–

AI-suggested

A fix is available and has been applied in Linux kernel version 3.19 and subsequent commits. Users and administrators should update to these fixed versions to mitigate the race condition and deadlock issues. No additional action is required beyond applying the official patch. Since this is a kernel-level fix, ensure that kernel updates are tested and deployed according to organizational policies.

Description

CVE-2026-31486 is a high-severity vulnerability in the Linux kernel's hwmon subsystem related to PMBus regulator operations. The issue arises because certain regulator functions accessing shared PMBus registers were not protected by a mutex, leading to potential race conditions. A direct mutex addition caused deadlocks due to nested locking scenarios. The fix reworks notification handling to use a worker function outside the mutex, preventing deadlocks and ensuring safe concurrent access.

References

Community reviews

Loading reviews…