Out-of-bounds WriteWeakness · CWE-787

CVE-2021-26383

HIGH · 7.9 CVSS v3.1 Published 2025-09-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
81/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Insufficient bounds checking in AMD TEE (Trusted Execution Environment) could allow an attacker with a compromised userspace to invoke a command with malformed arguments leading to out of bounds memory access, potentially resulting in loss of integrity or availability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Insufficient bounds checking in AMD TEE (Trusted Execution Environment) allows a compromised userspace application to invoke TEE commands with malformed arguments, triggering out-of-bounds memory access. This can lead to integrity or availability compromise within the trusted execution environment.

MitigationApply AMD-provided firmware updates for the TEE component once released. Identify and inventory systems utilizing AMD TEE functionality to prioritize patching.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify AMD hardware with TEE capability
    Check system for AMD processors or AMD GPUs that support TEE. Run 'lspci | grep -i amd' or check system information. Look for AMD Platform Security Processor (PSP), AMD Secure Processor, or AMD SEV (Secure Encrypted Virtualization) mentions in hardware specs.
    Affected if System contains AMD processor or GPU that supports Trusted Execution Environment features and the TEE component is present in the firmware
  2. Check AMD PSP/Secure Processor firmware version
    Retrieve the AMD Platform Security Processor firmware version. On Linux, this may be available via 'cat /sys/class/dmi/id/bios_version' or through vendor-specific tools like 'amd-psp-secure' or 'cpuid' command. Check AMD advisory for affected firmware version ranges.
    Affected if The PSP/Secure Processor firmware version falls within any vulnerable version range identified by AMD for this CVE
  3. Verify TEE functionality is enabled
    Check if AMD TEE/Trusted Execution Environment is actively enabled on the system. This can be verified through system configuration, BIOS settings (look for 'Secure Execution', 'TEE', 'PSP' settings), or by checking if applications are actively using TEE services (check for TEE-related daemons, drivers, or running processes).
    Affected if AMD TEE is enabled and actively running on the system, allowing userspace applications to invoke TEE commands
  4. Check for compromised userspace access
    Review system audit logs and security monitoring for any suspicious userspace applications attempting to invoke TEE commands with malformed arguments. Check for unusual patterns in TEE command invocations if such logging is available.
    Affected if A compromised or malicious userspace application has the ability to invoke TEE commands on the system

The system is affected if it contains AMD hardware with TEE capability, has a vulnerable PSP/Secure Processor firmware version, and has TEE functionality enabled, allowing potentially compromised userspace applications to exploit the bounds checking flaw.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply AMD-provided firmware updates for the TEE component once released. Identify and inventory systems utilizing AMD TEE functionality to prioritize patching.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-26383 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-26383 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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