Medium severity · published Oct 8, 2026
CVE-2026-107399
Mechanize sends credential headers to another origin after a meta refresh
6.8
CVSS
0.4%
EPSS
No
On KEV
Description
The Mechanize library is used for automating interaction with websites. Prior to 2.14.1, Mechanize 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, and the exposure is limited to caller-supplied default headers. This issue is fixed in version 2.14.1.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ME
mechanize · sparklemotion
< 2.15.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-107399
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107399
x_refsource_CONFIRM
https://github.com/sparklemotion/mechanize/security/advisories/GHSA-c6rp-p8xm-4q9f
x_refsource_MISC
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/84c74df87d15f5d119df268ba6aa79bc1e16a2c3
x_refsource_MISC
https://github.com/sparklemotion/mechanize/releases/tag/v2.14.1
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