CVE-2026-107715 Mechanize sends credential headers to another host after an HTTP redirect
Mechanize leaks credential headers to attacker-controlled hosts during redirects, allowing capture of bearer tokens or session cookies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-107715?
CVE-2026-107715 is a medium-severity vulnerability in sparklemotion mechanize, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2026-107715?
2 open source packages ship an affected version, including mechanize.
| Package | Affected | Fixed in |
|---|---|---|
mechanize RubyGems | All versions | 2.14.1 |
mechanize RubyGems | All versions | 2.14.1 |
How do I fix CVE-2026-107715?
Upgrade mechanize to 2.14.1 or later.
Is CVE-2026-107715 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107715 exists.
Sources
Also known as DEBIAN-CVE-2026-107715, GHSA-2mwr-xjcg-37j7, UBUNTU-CVE-2026-107715.