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Actively exploited

CVE-2021-28663 Arm Mali Graphics Processing Unit (GPU) Use-After-Free Vulnerability

Arm Mali Graphics Processing Unit (GPU) kernel driver contains a use-after-free vulnerability that may allow a non-privileged user to make improper operations on GPU memory to gain root privilege, and/or disclose information.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch urgentlyCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
  • Rated High severity (CVSS 8.8, scored by CISA).
  • It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

The Arm Mali GPU kernel driver allows privilege escalation or information disclosure because GPU memory operations are mishandled, leading to a use-after-free. This affects Bifrost r0p0 through r28p0 before r29p0, Valhall r19p0 through r28p0 before r29p0, and Midgard r4p0 through r30p0.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for Arm Mali Graphics Processing Unit (GPU). Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply updates per vendor instructions.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Vendor Advisories

Regulation

The Compliance Clock

Cyber EssentialsRated high, so if it affects devices in your Cyber Essentials scope, the update must be installed within 14 days of the vendor releasing it.NIS2If exploitation causes a significant incident, essential and important entities owe their CSIRT an early warning within 24 hours and a notification within 72 hours.DORAFinancial entities must classify ICT incidents and send an initial notification for a major incident within strict deadlines, with exploited flaws a common cause.US federal (BOD 22-01)Federal civilian agencies had until 17 Nov 2021 to remediate. A sensible benchmark for everyone else.

General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.

Stay Ahead

More Exploited Arm Flaws

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CVE-2024-4610Arm Mali GPU Kernel Driver Use-After-Free VulnerabilityAdded 12 Jun 2024CVE-2023-4211Arm Mali GPU Kernel Driver Use-After-Free VulnerabilityAdded 3 Oct 2023CVE-2021-29256Arm Mali GPU Kernel Driver Use-After-Free VulnerabilityAdded 7 Jul 2023CVE-2023-26083Arm Mali GPU Kernel Driver Information Disclosure VulnerabilityAdded 7 Apr 2023CVE-2022-38181Arm Mali GPU Kernel Driver Use-After-Free VulnerabilityAdded 30 Mar 2023CVE-2022-22706Arm Mali GPU Kernel Driver Unspecified VulnerabilityAdded 30 Mar 2023

All 9 exploited Arm vulnerabilities

Not Sure If You Are Exposed?

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Evidence

Sources

  1. CISA Known Exploited Vulnerabilities catalogue
  2. NVD: CVE-2021-28663
  3. CVE record: CVE-2021-28663
  4. FIRST EPSS
  5. developer.arm.com/support/arm-security-updates
  6. developer.arm.com/support/arm-security-updates/mali-gpu-kernel-driver
  7. github.com/lntrx/CVE-2021-28663