CVE-2026-63852

Local code execution via unsupported user fences

Published Jul 19, 2026 · Updated Jul 19, 2026

Memory corruption in the AMDGPU VCN 4.0.3 encoder ring in Linux Kernel allows local users to corrupt GPU memory via a user fence. The ring-function table omits the no_user_fence flag, so DRM_IOCTL_AMDGPU_CS accepts a 64-bit user-fence chunk that unsupported VCN hardware writes to the wrong GPU address. Reachability requires affected VCN 4.0.3 hardware and render-node access; the write primitive can disclose or corrupt mapped data, execute code, or hang the GPU.

CVSS severity7.8
High
EPSS probability0.13%
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 4.0.3 encoder ring in Linux Kernel allows local users to corrupt GPU memory via a user fence. The ring-function table omits the no_user_fence flag, so DRM_IOCTL_AMDGPU_CS accepts a 64-bit user-fence chunk that unsupported VCN hardware writes to the wrong GPU address. Reachability requires affected VCN 4.0.3 hardware and render-node access; the write primitive can disclose or corrupt mapped data, execute code, or hang the GPU.

The record

CVE
CVE-2026-63852
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
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=6.5
  2. Affected versionversion=b889ef4ac98837838c38f7b9f72bba2f33ee367d <0177ac6141c8857130cf365369c74dee7b6b1f7f
  3. Affected versionversion=b889ef4ac98837838c38f7b9f72bba2f33ee367d <387b7c7667bd5c53549350ddad866d2fcf75a529
  4. Affected versionversion=b889ef4ac98837838c38f7b9f72bba2f33ee367d <4532b52b34e4e4310386e6fdf6a643368599f522
  5. Affected versionversion=b889ef4ac98837838c38f7b9f72bba2f33ee367d <9076a83e5adefd10dc5c967c7b8bde601c4c512a
  6. Affected versionversion=b889ef4ac98837838c38f7b9f72bba2f33ee367d <c12a5d35033c0640c57c10d7111c010c7b9c2c8e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.5; version=b889ef4ac98837838c38f7b9f72bba2f33ee367d <0177ac6141c8857130cf365369c74dee7b6b1f7f; version=b889ef4ac98837838c38f7b9f72bba2f33ee367d <387b7c7667bd5c53549350ddad866d2fcf75a529; version=b889ef4ac98837838c38f7b9f72bba2f33ee367d <4532b52b34e4e4310386e6fdf6a643368599f522; version=b889ef4ac98837838c38f7b9f72bba2f33ee367d <9076a83e5adefd10dc5c967c7b8bde601c4c512a; version=b889ef4ac98837838c38f7b9f72bba2f33ee367d <c12a5d35033c0640c57c10d7111c010c7b9c2c8e

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.

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

No sourced classifications are available.

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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