CVE-2026-31688

High

In the Linux kernel, the following vulnerability has been resolved: driver core: enforce device_lock for driver_match_device() Currently, driver_match_device() is called from three sites. One site (__device_attach_driver) holds device_lock(dev), but the other two (bind_store and __driver_attach) do not. This inconsistency means that bus match() callbacks are not guaranteed to be called with the lock held. Fix this by introducing driver_match_device_locked(), which guarantees holding the device lock using a scoped guard. Replace the unlocked calls in bind_store() and __driver_attach() with this new helper. Also add a lock assertion to driver_match_device() to enforce this guarantee. This consistency also fixes a known race condition. The driver_override implementation relies on the device_lock, so the missing lock led to the use-after-free (UAF) reported in Bugzilla for buses using this field. Stress testing the two newly locked paths for 24 hours with CONFIG_PROVE_LOCKING and CONFIG_LOCKDEP enabled showed no UAF recurrence and no lockdep warnings.

Package Linux Kernel
Published 2026-04-27
Last modified 2026-05-06
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2026-31688 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.30 and later are affected. Fixed in 7.0 and their respective stable series.

Affected from
≥ 2.6.30
Fixed in
✓ 7.0

References

The following references provide additional information about CVE-2026-31688 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2026-31688?

    CVE-2026-31688 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 2.6.30 onward and has been patched in 7.0. CVE-2026-31688 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31688?

    CVE-2026-31688 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-31688?

    Yes — CVE-2026-31688 has been patched. Fixed versions include 7.0. If you are running Linux kernel 2.6.30 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31688 actively exploited?

    No — CVE-2026-31688 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Use After Free (CWE-416)?

    The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →

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