CVE-2026-63850

Local privilege escalation via unsupported user-fence writes

Published Jul 19, 2026 · Updated Jul 19, 2026

Memory corruption in the AMDGPU VCN component of Linux Kernel allows local users to gain kernel privileges via a crafted fence submission. The VCN v5.0.0 encoder ring accepts AMDGPU_CHUNK_ID_FENCE through DRM_IOCTL_AMDGPU_CS even though its hardware lacks 64-bit user-fence support, causing misdirected GPU memory writes. Access to an AMDGPU render node and affected AMD VCN 5.0.0 hardware is required; the write primitive exposes kernel memory, permits kernel code execution, and can hang or crash the host.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in the AMDGPU VCN component of Linux Kernel allows local users to gain kernel privileges via a crafted fence submission. The VCN v5.0.0 encoder ring accepts AMDGPU_CHUNK_ID_FENCE through DRM_IOCTL_AMDGPU_CS even though its hardware lacks 64-bit user-fence support, causing misdirected GPU memory writes. Access to an AMDGPU render node and affected AMD VCN 5.0.0 hardware is required; the write primitive exposes kernel memory, permits kernel code execution, and can hang or crash the host.

The record

CVE
CVE-2026-63850
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-1287, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=6.9
  2. Affected versionversion=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <139a8a52ef4349c62129703b3a3e3a6ae4d634eb
  3. Affected versionversion=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <2c350f3cd94be847ac216e1358ec7001eaaf0934
  4. Affected versionversion=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <8cae0ce77de492d7c31c1532a2e80c0c6e7e58cb
  5. Affected versionversion=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <9f5a1459ecc3195282be617639d710b54779c9dc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.9; version=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <139a8a52ef4349c62129703b3a3e3a6ae4d634eb; version=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <2c350f3cd94be847ac216e1358ec7001eaaf0934; version=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <8cae0ce77de492d7c31c1532a2e80c0c6e7e58cb; version=b6d1a06320519ac3bfda6ce81067a1bc409b9cff <9f5a1459ecc3195282be617639d710b54779c9dc

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

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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-1287Improper Validation of Specified Type of Input
T1068Exploitation for Privilege Escalation

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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