CVE-2021-29256Known exploitation

Root privilege escalation via freed GPU memory access

Published May 24, 2021 · Updated Oct 21, 2025

Use-after-free in Arm Mali GPU kernel drivers allows local users to disclose information or gain root privileges through GPU operations. The driver permits an unprivileged process to access GPU memory after its backing allocation has been freed. Local unprivileged execution is required; affected releases are Bifrost r16p0 through r29p0, Valhall r19p0 through r29p0, and Midgard r28p0 through r30p0.

CVSS severity8.8
High
EPSS probability2.99%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Arm Mali GPU kernel drivers allows local users to disclose information or gain root privileges through GPU operations. The driver permits an unprivileged process to access GPU memory after its backing allocation has been freed. Local unprivileged execution is required; affected releases are Bifrost r16p0 through r29p0, Valhall r19p0 through r29p0, and Midgard r28p0 through r30p0.

The record

CVE
CVE-2021-29256
Published
May 24, 2021
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1068
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. May 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 7, 2023Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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