CVE-2026-107715

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.

References

• 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/pull/676
• https://github.com/sparklemotion/mechanize/releases/tag/v2.14.1