# CVE-2021-26386: Memory corruption in Athlon™ Series

> A malicious application can trigger memory corruption in the AMD Stage 2 Bootloader via malformed system calls, leading to arbitrary code execution.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 May 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-q5m8-56v3-xhv7

## What is CVE-2021-26386?

CVE-2021-26386 is a high-severity memory corruption vulnerability in AMD Athlon™ Series, published on 12 May 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A malicious or compromised UApp or ABL may be used by an attacker to issue a malformed system call to the Stage 2 Bootloader potentially leading to corrupt memory and code execution.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-26386?

It affects 70 products.


Products: Amd Ryzen 3 2200u Firmware, Amd Ryzen 3 2300u Firmware, Amd Ryzen 3 3100 Firmware, Amd Ryzen 3 3300g Firmware, Amd Ryzen 3 3300x Firmware, Amd Ryzen 3 5125c Firmware, Amd Ryzen 3 5400u Firmware, Amd Ryzen 3 5425c Firmware, Amd Ryzen 3 5425u Firmware, Amd Ryzen 5300g Firmware, Amd Ryzen 5300ge Firmware, Amd Ryzen 5600g Firmware, Amd Ryzen 5600ge Firmware, Amd Ryzen 5600x Firmware, Amd Ryzen 5700g Firmware, Amd Ryzen 5700ge Firmware, Amd Ryzen 5800x3d Firmware, Amd Ryzen 5800x Firmware, Amd Ryzen 5900x Firmware, Amd Ryzen 5950x Firmware and 50 more.

## How do I fix CVE-2021-26386?

No fix has been published for CVE-2021-26386 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26386 being exploited?

There is no known exploitation of CVE-2021-26386 in the wild and no public exploit code.

## Other vulnerabilities in AMD Athlon™ Series

- [CVE-2021-26368](https://insights.sbomify.com/CVE-2021-26368/): Privilege escalation in Athlon™ Series (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26386 and fix it if it is affected.

What it is: CVE-2021-26386 is a high-severity memory corruption vulnerability in AMD Athlon™ Series, published on 12 May 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-26386 in the wild and no public exploit code.

Affected product: AMD Athlon™ Series. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-26386/ (Markdown: https://insights.sbomify.com/CVE-2021-26386/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26386
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26386
- OSV: https://osv.dev/vulnerability/CVE-2021-26386

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26386/
Summaries are generated and may contain mistakes; the official description above is the record.