Medium (5.3). EPSS 5.5% chance of exploitation in the next 30 days.
Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1 allows an HTTP Response Splitting attack. An attacker can inject a crafted key and value into an HTTP response for the HTTP server of WEBrick.
Severity
CVSS 3.0
5.3 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
5.5% chance of exploitation in the next 30 days; higher than 92% of CVEs (scores of 2026-10-31)