CVE-2025-61921

Name of the Vulnerable Software and Affected Versions Sinatra versions prior to 4.2.0

Description Sinatra, a domain-specific language for creating web applications in Ruby, contains an issue where carefully crafted input can cause excessive processing time during the parsing of If-Match and If-None-Match headers. This occurs when the etag method is used to construct responses, potentially leading to a denial of service. The If-Match and If-None-Match headers are typically used in generating the ETag header value.

Recommendations Update to Sinatra version 4.2.0 or later.