CVE-2026-21385 is a high-severity vulnerability (CVSS 7.8) affecting the graphics subsystem of certain Android devices that use Qualcomm chipsets. The flaw exists in the Qualcomm Adreno GPU graphics driver, which is responsible for handling graphics processing and memory allocation.

The vulnerability results from an integer overflow (CWE-190) during memory allocation calculations. When the system incorrectly calculates the required memory buffer size, it can lead to memory corruption, allowing data to overflow into restricted memory areas.

The vulnerability impacts Android devices using Qualcomm chipsets, specifically those that rely on the Qualcomm graphics component within the Android ecosystem.

Affected environments include:

• Android smartphones and tablets using Qualcomm Snapdragon chipsets.
• Devices using the Qualcomm Adreno GPU driver within the Android graphics stack.
• Android builds prior to the March 2026 Android security patch level.

Attackers can exploit the vulnerability through malicious applications or specially crafted requests that interact with the graphics driver.

Typical exploitation process:

1. Triggering the calculation error
   • A malicious app sends specially crafted input to the GPU driver.
   • The driver miscalculates the size of the memory buffer due to an integer overflow.
2. Memory corruption occurs
   • The system allocates insufficient memory for the data being processed.
   • The excess data overflows into adjacent memory areas.
3. Privilege escalation
   • Attackers may leverage the corrupted memory to bypass Android security restrictions.
4. Potential attacker outcomes
   • Gain elevated system privileges.
   • Execute arbitrary code on the device.
   • Access sensitive user data such as messages, camera, or files.

In targeted attacks, such exploits are often combined with spyware or other privilege-escalation exploits to fully compromise mobile devices.

CERTVU recommend:

Immediate Mitigation

1. Apply Security Updates Immediately
2. Update Device Firmware