# CVE-2026-11891: Arm Valhall GPU Userspace Driver use-after-free vulnerability

Source: https://junglewise.ai/threats/cve-2026-11891-arm-valhall-gpu-userspace-driver-use-after-free-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-11891 · Severity: medium · CVSS 5.1 · Published 2026-09-08

Arm's Valhall GPU Userspace Driver contains a use-after-free vulnerability that allows an unprivileged user to access memory that has already been freed by the GPU. An attacker can trigger this flaw through normal GPU operations, including web-based graphics APIs like WebGL or WebGPU, potentially leading to information disclosure or denial of service.

Vendors: [Arm](https://junglewise.ai/threats/vendors/arm).

## Quick answers

**Is CVE-2026-11891 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-11891 being exploited in the wild.

**How severe is CVE-2026-11891?** Medium severity, with a CVSS score of 5.1, published 8 September 2026.

**Which products and versions are affected?** Arm 5th Gen GPU Architecture Userspace Driver r46p0 through r49p5, r50p0 through r54p3, r55p0; Arm Valhall GPU Userspace Driver r46p0 through r49p5, r50p0 through r54p3, r55p0.

**Is there a fix for CVE-2026-11891?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-11891 attacked?** It is attacked over the network or with local access.

**Am I affected by CVE-2026-11891?** Check whether you run Arm 5th Gen GPU Architecture Userspace Driver or Arm Valhall GPU Userspace Driver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A use-after-free vulnerability exists in the Valhall GPU Userspace Driver's memory management logic. The vulnerability is triggered when a non-privileged user process performs valid GPU processing operations via WebGL or WebGPU interfaces, accessing memory regions that have already been deallocated. The flaw allows an attacker to read or corrupt freed memory without requiring elevated privileges or special system configuration. Arm has released patches addressing this issue across affected driver versions.

## Affected products

- Arm Valhall GPU Userspace Driver r46p0 through r49p5, r50p0 through r54p3, r55p0
- Arm Arm 5th Gen GPU Architecture Userspace Driver r46p0 through r49p5, r50p0 through r54p3, r55p0

## Timeline

- 2026-09-08: disclosed

## References

- [https://support.arm.com/documentation/111552/1-0/?lang=en](https://support.arm.com/documentation/111552/1-0/?lang=en)

## Related threats

- [Arm Bifrost GPU Userspace Driver use-after-free vulnerability](https://junglewise.ai/threats/cve-2026-9034-arm-bifrost-gpu-userspace-driver-use-after-free-vulnerability)