Insertion of Sensitive Information Into Sent Data Affecting mechanize package, versions <2.14.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RUBY-MECHANIZE-21716801
- published26 Oct 2026
- disclosed8 Oct 2026
- creditflavorjones
Introduced: 8 Oct 2026
NewCVE-2026-107399 (opens in a new tab)How to fix?
Upgrade mechanize to version 2.14.1 or higher.
Overview
Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data via the response_follow_meta_refresh function in Mechanize::HTTP::Agent. An attacker who can place a meta refresh in a page the agent fetches can point it to another origin and capture bearer tokens or session cookies configured through Mechanize#request_headers=. This requires follow_meta_refresh to be enabled, which is false by default.
Workarounds
- Leave
Mechanize#follow_meta_refreshat its default value offalseto prevent the agent from following attacker-controlled meta refreshes. - If meta refresh following is enabled, avoid setting credentials through
Mechanize#request_headers=to prevent those credentials from being sent to a cross-origin refresh target.