# CVE-2021-26336: Memory corruption in Athlon™ Series

> Insufficient bounds checking in AMD SMU firmware allows invalid memory access, causing system hang and denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 16 Nov 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-g84m-4q6r-8c89

## What is CVE-2021-26336?

CVE-2021-26336 is a medium-severity memory corruption vulnerability in Amd Epyc 7232p Firmware, published on 16 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and subsequent failure to service any further requests from other components.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-26336?

It affects 95 products.


Products: Amd Epyc 7002 Firmware, Amd Epyc 7003 Firmware, Amd Epyc 7232p Firmware, Amd Epyc 7252 Firmware, Amd Epyc 7262 Firmware, Amd Epyc 7272 Firmware, Amd Epyc 7282 Firmware, Amd Epyc 72f3 Firmware, Amd Epyc 7302 Firmware, Amd Epyc 7302p Firmware, Amd Epyc 7313 Firmware, Amd Epyc 7313p Firmware, Amd Epyc 7343 Firmware, Amd Epyc 7352 Firmware, Amd Epyc 73f3 Firmware, Amd Epyc 7402 Firmware, Amd Epyc 7402p Firmware, Amd Epyc 7413 Firmware, Amd Epyc 7443 Firmware, Amd Epyc 7443p Firmware and 75 more.

## How do I fix CVE-2021-26336?

No fix has been published for CVE-2021-26336 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26336 being exploited?

There is no known exploitation of CVE-2021-26336 in the wild and no public exploit code.

## Other vulnerabilities in Amd Epyc 7232p Firmware

- [CVE-2020-12961](https://insights.sbomify.com/CVE-2020-12961/): Security feature bypass in 2nd Gen AMD EPYC™ (high 7.8)
- [CVE-2023-20529](https://insights.sbomify.com/CVE-2023-20529/): Denial of service in 2nd Gen EPYC (high 7.5)
- [CVE-2023-20531](https://insights.sbomify.com/CVE-2023-20531/): Denial of service in 2nd Gen EPYC (high 7.5)
- [CVE-2021-26402](https://insights.sbomify.com/CVE-2021-26402/): Memory corruption in 2nd Gen EPYC (high 7.1)
- [CVE-2021-26370](https://insights.sbomify.com/CVE-2021-26370/): Memory corruption in 2nd Gen AMD EPYC™ (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26336 and fix it if it is affected.

What it is: CVE-2021-26336 is a medium-severity memory corruption vulnerability in Amd Epyc 7232p Firmware, published on 16 Nov 2021. 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-2021-26336 in the wild and no public exploit code.

Affected product: Amd Epyc 7232p Firmware. 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-2021-26336/ (Markdown: https://insights.sbomify.com/CVE-2021-26336/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26336
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26336
- OSV: https://osv.dev/vulnerability/CVE-2021-26336

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-26336/
Summaries are generated and may contain mistakes; the official description above is the record.