# CVE-2026-21736: GPU DDK - Insufficient permission check in PhysmemWrapExtMem() when write attribute support enabled

> A non-privileged user can gain write access to read-only memory via improper GPU system calls, requiring write attribute support to be enabled.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Mar 2026
- **Updated:** 9 Mar 2026
- **Also known as:** A-382331631, ASB-A-382331631, GHSA-vjrg-fwqx-82jx

## What is CVE-2026-21736?

CVE-2026-21736 is a medium-severity vulnerability in Imagination Technologies Graphics DDK, published on 9 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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 is caused by improper handling of the memory protections for the user-mode wrapped memory resource.

Weakness: CWE-280 (Improper Handling of Insufficient Permissions or Privileges)

## Which versions are affected by CVE-2026-21736?

It affects 1 product.


Products: Imaginationtech Ddk.

## How do I fix CVE-2026-21736?

Apply the vendor's patch.

## Is CVE-2026-21736 being exploited?

There is no known exploitation of CVE-2026-21736 in the wild and no public exploit code.

## Other vulnerabilities in Imagination Technologies Graphics DDK

- [CVE-2026-16280](https://insights.sbomify.com/CVE-2026-16280/): GPU DDK - Integer overflow in _PMRLogicalOffsetToPhysicalOffset (critical 9.8)
- [CVE-2025-13952](https://insights.sbomify.com/CVE-2025-13952/): GPU DDK - libusc UAF via WebGPU shaders at MergeConsecutiveBarriersBP (critical 9.8)
- [CVE-2026-21732](https://insights.sbomify.com/CVE-2026-21732/): GPU DDK - libusc OOB write at ConvertSwitchToArrayLookupBP during WebGPU shader compilation (critical 9.6)
- [CVE-2025-25176](https://insights.sbomify.com/CVE-2025-25176/): GPU DDK - GPU Register value contents leaked from secure workloads to non-secure world (critical 9.1)
- [CVE-2025-58411](https://insights.sbomify.com/CVE-2025-58411/): GPU DDK - Reservation::psMappedPMR can change while used by a freelist -> UAF (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21736 and fix it if it is affected.

What it is: CVE-2026-21736 is a medium-severity vulnerability in Imagination Technologies Graphics DDK, published on 9 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-21736 in the wild and no public exploit code.

Affected product: Imagination Technologies Graphics DDK. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-21736/ (Markdown: https://insights.sbomify.com/CVE-2026-21736/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21736
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21736
- OSV: https://osv.dev/vulnerability/CVE-2026-21736

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21736/
Summaries are generated and may contain mistakes; the official description above is the record.