CVE-2026-68445

Local shader validation bypass via writable mappings

Published Aug 12, 2026 · Updated Aug 12, 2026

Improper validation in the Linux vc4 DRM driver allows local users to rewrite validated shader code through a mapping permission upgrade. The vc4_gem_object_mmap() path rejects writable mappings but retains VM_MAYWRITE, so mprotect() can make a read-only shader buffer writable after validation. Exploitation requires local low-privileged access and vc4 graphics hardware; modified instructions bypass the validator and allow unauthorized GPU access to system memory.

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

Improper validation in the Linux vc4 DRM driver allows local users to rewrite validated shader code through a mapping permission upgrade. The vc4_gem_object_mmap() path rejects writable mappings but retains VM_MAYWRITE, so mprotect() can make a read-only shader buffer writable after validation. Exploitation requires local low-privileged access and vc4 graphics hardware; modified instructions bypass the validator and allow unauthorized GPU access to system memory.

The record

CVE
CVE-2026-68445
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-179, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 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=4.5
  2. Affected versionversion=463873d5701427f2964a0b4b72c45f1f14b6df87 <019e6ad247f7fd038d2e009789f6d9bfcccb1ae7
  3. Affected versionversion=463873d5701427f2964a0b4b72c45f1f14b6df87 <0c9e6367639548307d3f578f6943ce72c9d39087
  4. Affected versionversion=463873d5701427f2964a0b4b72c45f1f14b6df87 <6deaa317201851c644c431b57682e54d06b35838
  5. Affected versionversion=463873d5701427f2964a0b4b72c45f1f14b6df87 <9f0ee411fc2d76333d6087c5862ffa907cf7a175
  6. Affected versionversion=463873d5701427f2964a0b4b72c45f1f14b6df87 <fe168ef1d232d734d9998fd74822e2e20930dfff

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.5; version=463873d5701427f2964a0b4b72c45f1f14b6df87 <019e6ad247f7fd038d2e009789f6d9bfcccb1ae7; version=463873d5701427f2964a0b4b72c45f1f14b6df87 <0c9e6367639548307d3f578f6943ce72c9d39087; version=463873d5701427f2964a0b4b72c45f1f14b6df87 <6deaa317201851c644c431b57682e54d06b35838; version=463873d5701427f2964a0b4b72c45f1f14b6df87 <9f0ee411fc2d76333d6087c5862ffa907cf7a175; version=463873d5701427f2964a0b4b72c45f1f14b6df87 <fe168ef1d232d734d9998fd74822e2e20930dfff

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8UbuntuCVSS: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

CWE-179Incorrect Behavior Order: Early Validation
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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