CVE-2025-61921

Description

Sinatra is a domain-specific language for creating web applications in Ruby. In versions prior to 4.2.0, there is a denial of service vulnerability in the `If-Match` and `If-None-Match` header parsing component of Sinatra, if the `etag` method is used when constructing the response. Carefully crafted input can cause `If-Match` and `If-None-Match` header parsing in Sinatra to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is typically involved in generating the `ETag` header value. Any applications that use the `etag` method when generating a response are impacted. Version 4.2.0 fixes the issue.

Weakness classification

• security-advisories@github.com: CWE-1333

Primary references

• security-advisories@github.com — Issue Tracking
• security-advisories@github.com — Issue Tracking
• security-advisories@github.com — Exploit, Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Vendor Advisory