# CVE-2021-26313: AMD Speculative Code Store Bypass

> Speculative execution flaws in AMD CPUs may allow attackers to leak sensitive data via side-channel attacks.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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:** Yes
- **Published:** 9 Jun 2021
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2021-26313, GHSA-vj56-jg6h-3gpr, UBUNTU-CVE-2021-26313

## What is CVE-2021-26313?

CVE-2021-26313 is a medium-severity vulnerability in Debian Debian Linux, published on 9 Jun 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Potential speculative code store bypass in all supported CPU products, in conjunction with software vulnerabilities relating to speculative execution of overwritten instructions, may cause an incorrect speculation and could result in data leakage.

Weakness: CWE-203 (Observable Discrepancy), CWE-208 (Observable Timing Discrepancy)

## Which versions are affected by CVE-2021-26313?

It affects 8 products.


Products: Arm Cortex-A72, Broadcom Bcm2711, Debian Debian Linux, Intel Core I7-10700k, Intel Core I7-7700k, Intel Core I9-9900k, Intel Xeon Silver 4214, Xen Xen.

## How do I fix CVE-2021-26313?

Apply the vendor's patch.

## Is CVE-2021-26313 being exploited?

There is no known exploitation of CVE-2021-26313 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2021-26314](https://insights.sbomify.com/CVE-2021-26314/): AMD Speculative execution with Floating-Point Value Injection (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26313 and fix it if it is affected.

What it is: CVE-2021-26313 is a medium-severity vulnerability in Debian Debian Linux, published on 9 Jun 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-2021-26313 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2021-26313/ (Markdown: https://insights.sbomify.com/CVE-2021-26313/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26313
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26313
- OSV: https://osv.dev/vulnerability/CVE-2021-26313

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26313/
Summaries are generated and may contain mistakes; the official description above is the record.