CVE-2026-107715
MediumCVSS 6.8Summary
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.
Risk Assessment
An attacker controlling a redirect target can capture sensitive headers such as bearer tokens or session cookies, potentially leading to unauthorized access or identity theft.
Recommendation
Update Mechanize to version 2.14.1 or later. Additionally, avoid passing sensitive headers via request_headers= or consider using more secure authentication mechanisms.
Other vulnerabilities in Mechanize
See all- CVE-2026-107714Medium
The Mechanize library before version 2.14.1 incorrectly treats redirects as same-origin when the host matches without consistently comparing scheme and port. A same-host HTTPS-to-HTTP redirect can send Authorization and Cookie headers over cleartext, while a same-host redirect to another port can send a caller-supplied Cookie header to a different service. The issue affects caller-supplied headers and can disclose credentials.
- CVE-2026-107399Medium
The Mechanize library before version 2.14.1 applies no origin trust boundary in Mechanize::HTTP::Agent#response_follow_meta_refresh when Mechanize#follow_meta_refresh is enabled. A page containing a meta refresh to another origin causes headers configured through Mechanize#request_headers= to be reapplied to the refresh request, allowing an attacker who controls content in the crawl to capture bearer tokens or session cookies. The default configuration is not affected because follow_meta_refresh is false.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS