Medium (6.1) in rubyonrails rails. EPSS 1.2% chance of exploitation in the next 30 days. Fixed in actionpack 6.1.3.2.
The actionpack ruby gem before 6.1.3.2 suffers from a possible open redirect vulnerability. Specially crafted Host headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. This is similar to CVE-2021-22881. Strings in config.hosts that do not have a leading dot are converted to regular expressions without proper escaping. This causes, for example, `config.hosts << "sub.example.com"` to permit a request with a Host header value of `sub-example.com`.
Severity
CVSS 3.1
6.1 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
1.2% chance of exploitation in the next 30 days; higher than 68% of CVEs (scores of 2026-10-31)