CVE-2026-21736: Imaginationtech DDK Privilege Escalation

CVE-2026-21736 Overview

CVE-2026-21736 is a memory protection bypass vulnerability in the Imagination Technologies GPU Driver Development Kit (DDK). Software installed and run as a non-privileged user may conduct improper GPU system calls to gain write permission to read-only wrapped user-mode memory. This vulnerability stems from improper handling of memory protections for user-mode wrapped memory resources.

Critical Impact

Non-privileged users can exploit improper GPU system calls to gain unauthorized write access to read-only memory regions, potentially leading to privilege escalation or data manipulation.

Affected Products

• Imagination Technologies DDK version 25.1
• Imagination Technologies DDK version 25.1 RTM2

Discovery Timeline

• 2026-03-09 - CVE-2026-21736 published to NVD
• 2026-03-10 - Last updated in NVD database

Technical Details for CVE-2026-21736

Vulnerability Analysis

This vulnerability is classified under CWE-280 (Improper Handling of Insufficient Permissions or Privileges). The flaw exists in how the Imagination Technologies DDK handles memory protection attributes for user-mode wrapped memory resources during GPU system calls.

When a non-privileged application interacts with the GPU driver through specific system calls, the driver fails to properly validate and enforce memory protection flags. This allows an attacker to manipulate read-only memory regions that should be protected, potentially enabling unauthorized data modification or privilege escalation scenarios.

The local attack vector requires the attacker to have local access and some level of privileges on the target system. While the vulnerability does not directly lead to code execution, the ability to write to protected memory regions creates opportunities for further exploitation in multi-stage attacks.

Root Cause

The root cause lies in the GPU driver's improper handling of memory protections for user-mode wrapped memory resources. When processing GPU system calls, the driver fails to correctly enforce the read-only attribute on wrapped user-mode memory, allowing write operations that should be denied.

This insufficient permission checking mechanism allows non-privileged processes to bypass memory protection boundaries that are essential for system integrity and security isolation.

Attack Vector

The attack requires local access to the system with a non-privileged user account. The attacker must be able to install and execute software that makes GPU system calls. The exploitation path involves:

1. The attacker installs a malicious application running as a non-privileged user
2. The application makes specially crafted GPU system calls targeting wrapped user-mode memory
3. Due to improper permission handling, the driver grants write access to memory marked as read-only
4. The attacker can then modify protected memory contents, potentially leading to privilege escalation or data tampering

The vulnerability affects the confidentiality and integrity of data, though it does not directly impact system availability.

Detection Methods for CVE-2026-21736

Indicators of Compromise

• Unusual GPU system call patterns from non-privileged processes attempting to access protected memory regions
• Unexpected modifications to read-only memory mappings associated with GPU operations
• Anomalous driver behavior or errors in GPU subsystem logs indicating permission violations

Detection Strategies

• Monitor GPU driver activity for unusual memory mapping operations from low-privilege processes
• Implement endpoint detection rules to identify applications making suspicious GPU system calls
• Audit running processes for unauthorized software interacting with GPU driver interfaces

Monitoring Recommendations

• Enable verbose logging for GPU driver operations where supported
• Deploy behavioral analysis solutions capable of detecting memory protection bypass attempts
• Regularly audit installed software to identify potentially malicious applications targeting GPU vulnerabilities

How to Mitigate CVE-2026-21736

Immediate Actions Required

• Update Imagination Technologies DDK to the latest patched version as specified in the vendor security advisory
• Restrict local access and software installation privileges on systems with vulnerable GPU drivers
• Monitor systems for suspicious GPU-related activity until patches can be applied

Patch Information

Imagination Technologies has released security information regarding this vulnerability. Organizations should consult the Imagination Technologies Security Advisory for detailed patch information and updated driver versions that address CVE-2026-21736.

Workarounds

• Limit software installation privileges to trusted administrators only
• Implement application allowlisting to prevent unauthorized software from executing GPU system calls
• Consider isolating systems with vulnerable drivers from untrusted users until patches are applied
• Use SentinelOne's behavioral AI to detect and block exploitation attempts targeting this vulnerability