CVE-2026-21733

Local memory overwrite via invalid reservation flags

Published Apr 17, 2026 · Updated Apr 17, 2026

Improper permission handling in Imagination Technologies Graphics DDK 25.3 RTM and earlier allows local users to overwrite read-only memory. RGXDerivePTEProt8 accepts invalid access flags when creating a GPU memory reservation, overriding the wrapped mapping's read-only permissions. Local low-privileged code must issue crafted GPU system calls; successful exploitation permits GPU writes to shared user-mode memory such as libc.so.

CVSS severity7.3
High
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper permission handling in Imagination Technologies Graphics DDK 25.3 RTM and earlier allows local users to overwrite read-only memory. RGXDerivePTEProt8 accepts invalid access flags when creating a GPU memory reservation, overriding the wrapped mapping's read-only permissions. Local low-privileged code must issue crafted GPU system calls; successful exploitation permits GPU writes to shared user-mode memory such as libc.so.

The record

CVE
CVE-2026-21733
Published
Apr 17, 2026
Updated
Apr 17, 2026
Vendor
Imagination Technologies
Product
Graphics DDK
Classifications
CWE-20, CWE-280, CAPEC-679, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 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=1.17 RTM
  2. Affected versionversion=1.18 RTM
  3. Affected versionversion=23.2 RTM
  4. Affected versionversion=24.1 RTM <=24.2 RTM
  5. Affected versionversion=25.1 RTM <=25.3 RTM

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Imagination Technologies · Graphics DDKversion=1.17 RTM; version=1.18 RTM; version=23.2 RTM; version=24.1 RTM <=24.2 RTM; version=25.1 RTM <=25.3 RTM

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

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-20Improper Input Validation
CWE-280Improper Handling of Insufficient Permissions or Privileges
CAPEC-679Exploitation of Improperly Configured or Implemented Memory Protections
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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