CVE-2021-29256

Exp

. The Arm Mali GPU kernel driver allows an unprivileged user to achieve access to freed memory, leading to information disclosure or root privilege escalation. This affects Bifrost r16p0 through r29p0 before r30p0, Valhall r19p0 through r29p0 before r30p0, and Midgard r28p0 through r30p0.

Published: 2021-05-24 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-29256 is rated Critical Active Threat (85.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.66%). Core evidence: CISA KEV confirms active exploitation (added 2023-07-07) affecting Arm / Mali Graphics Processing Unit (GPU). a weakness (CWE-416) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-29256

Name: Arm Mali GPU Kernel Driver Use-After-Free Vulnerability · CISA KEV detail

Exploit added: 2023-07-07

Action due: 2023-07-28

Required action: Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.

Exploit prediction scoring system (EPSS) score for CVE-2021-29256

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-26 0.53% 0.66% +0.14%
2 2026-03-06 0.64% 0.53% -0.11%
3 2025-11-21 0.64%

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29256

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
9.0 2.0 HIGH
AV:N/AC:L/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.0 10.0 [email protected]

Weakness enumeration for CVE-2021-29256

OS Trackers for CVE-2021-29256

vendor priority summary link
suse high CVE-2021-29256 severity important: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 420 product×package rows across 83 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (83 product lines)): Known Not Affected 420. https://www.suse.com/security/cve/CVE-2021-29256/

Affected software / configurations for CVE-2021-29256

Vendor Product Version Raw CPE
arm bifrost_gpu_kernel_driver >= r16p0, < r30p0 cpe:2.3:a:arm:bifrost_gpu_kernel_driver:*:*:*:*:*:*:*:*
arm midgard_gpu_kernel_driver >= r28p0, < r31p0 cpe:2.3:a:arm:midgard_gpu_kernel_driver:*:*:*:*:*:*:*:*
arm valhall_gpu_kernel_driver >= r19p0, < r30p0 cpe:2.3:a:arm:valhall_gpu_kernel_driver:*:*:*:*:*:*:*:*

References for CVE-2021-29256

cvelogic Threat Intelligence