IRONSMITHINTEL
HIGHCVSS8.8
|
Actively Exploited
|CISA KEV|CVE-2021-28663|Auth: low — authenticated user|Reboot: required|Manual only

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

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.

Published May 10, 2021 · Updated May 17, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, with a low-privilege account, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2021-11-17 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Use After Free (CWE-416) vulnerability in Arm Mali Graphics Processing Unit (GPU). 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. Exploitation requires remote network access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running bifrost gpu kernel driver: r0p0 ≤ v < r29p0; midgard gpu kernel driver: r4p0 ≤ v < r31p0; valhall gpu kernel driver: r19p0 ≤ v < r29p0
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://github.com/lntrx/CVE-2021-28663

How to patch

Manual remediation steps

1
Identify affected hosts: query inventory for general installs in scope.
2
Apply the vendor security update referenced in CVE-2021-28663's advisory. No specific KB/version is encoded yet — consult the linked MSRC/vendor URL.
3
Verify the fix per the vendor's published verification steps.
4
Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.
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