Vulnerability · Published Oct 8, 2026 · Assigned by GitHub_M

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

Medium 6.8

In plain English

A medium-severity information exposure in mechanize from sparklemotion. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.5%top 56.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	ruby-mechanize	no fix listed	DEBIAN-CVE-2026-107715
Debian:13	ruby-mechanize	no fix listed	DEBIAN-CVE-2026-107715
Debian:14	ruby-mechanize	2.14.1-1	DEBIAN-CVE-2026-107715
RubyGems	mechanize	2.14.1	GHSA-2mwr-xjcg-37j7
Ubuntu:22.04:LTS	ruby-mechanize	no fix listed	UBUNTU-CVE-2026-107715
Ubuntu:24.04:LTS	ruby-mechanize	no fix listed	UBUNTU-CVE-2026-107715
Ubuntu:26.04:LTS	ruby-mechanize	no fix listed	UBUNTU-CVE-2026-107715
Ubuntu:26.10	ruby-mechanize	no fix listed	UBUNTU-CVE-2026-107715

Affected products (as reported)

Vendor	Product	Versions
sparklemotion	mechanize	< 2.15.0

Weakness: CWE-200, CWE-522 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

References

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