URI allows for userinfo Leakage in URI#join, URI#merge, and URI#+

There is a possibility for userinfo leakage by in the uri gem. This vulnerability has been assigned the CVE identifier CVE-2025-27221. We recommend upgrading the uri gem.

Details

The methods URI#join, URI#merge, and URI#+ retained userinfo, such as user:password, even after the host is replaced. When generating a URL to a malicious host from a URL containing secret userinfo using these methods, and having someone access that URL, an unintended userinfo leak could occur.

Please update URI gem to version 0.11.3, 0.12.4, 0.13.2, 1.0.3 or later.

Affected versions

uri gem versions < 0.11.3, 0.12.0 to 0.12.3, 0.13.0, 0.13.1 and 1.0.0 to 1.0.2.

Credits

Thanks to Tsubasa Irisawa (lambdasawa) for discovering this issue. Also thanks to nobu for additional fixes of this vulnerability.