CVE-2026-43305

System hang via mismatched DMUB unlock

Published May 8, 2026 · Updated May 8, 2026

Improper locking in Linux Kernel 6.19 through 6.19.5 allows local users to hang systems through the AMD display fast path. The HWSS fast path evaluates DMUB hardware-lock use and unlock eligibility with different conditions, causing an unlock when no lock was taken. Reachability requires an AMD ASIC without FAMS support and local low-privileged access; the consequence is an availability-only system hang.

CVSS severity5.5
Medium
EPSS probability0.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in Linux Kernel 6.19 through 6.19.5 allows local users to hang systems through the AMD display fast path. The HWSS fast path evaluates DMUB hardware-lock use and unlock eligibility with different conditions, causing an unlock when no lock was taken. Reachability requires an AMD ASIC without FAMS support and local low-privileged access; the consequence is an availability-only system hang.

The record

CVE
CVE-2026-43305
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e387ad67efb100b645630ffbce7716786f52283
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <af3303970da5ce5bfe6dffdd07f38f42aad603e0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e387ad67efb100b645630ffbce7716786f52283; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <af3303970da5ce5bfe6dffdd07f38f42aad603e0

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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