BaselineWatch
Desk
Your fleet and your work Fleetyour releases and the hardware they run onTriagewhat needs a decisionWatchlistthe products and platforms you runSaved searchesthe lists you come back to
This instance Sourceswhat is read, how often, under what termsDigestthe daily or weekly summary, and alerts
How it is drawn Appearancethe look and the colour schemeBrandingthe mark this instance wears
Owner sign-in

CVE-2025-61921

2.7 low SSVC exploitation: none Analyzed
NVD · CVE.org

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.

Fix

Patch, vendor advisory and mitigation references on NVD 3

Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.

Change history 1

  1. First seenCVSS 2.7 · sinatrarbNVD modified 2026-10-19 16:10

Affected (CPE criteria) 1

  • cpe:2.3:a:sinatrarb:sinatra:*:*:*:*:*:*:*:*

References 5