CVE-2025-61921

NameCVE-2025-61921
DescriptionSinatra 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
ruby-sinatra (PTS)bullseye2.0.8.1-2vulnerable
bullseye (security)2.0.8.1-2+deb11u1vulnerable
bookworm3.0.5-3vulnerable
trixie4.1.1-5vulnerable
forky, sid4.1.1-6vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
ruby-sinatrasource(unstable)(unfixed)

Notes

https://github.com/sinatra/sinatra/security/advisories/GHSA-mr3q-g2mv-mr4q
https://github.com/sinatra/sinatra/issues/2120
https://github.com/sinatra/sinatra/pull/1823
https://github.com/sinatra/sinatra/pull/2121
https://bugs.ruby-lang.org/issues/19104

Search for package or bug name: Reporting problems