CVE-2025-61921: Sinatra is vulnerable to ReDoS through ETag header value generation
(updated )
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 and you are using Ruby < 3.2.
References
- bugs.ruby-lang.org/issues/19104
- github.com/advisories/GHSA-mr3q-g2mv-mr4q
- github.com/rubysec/ruby-advisory-db/blob/master/gems/sinatra/CVE-2025-61921.yml
- github.com/sinatra/sinatra
- github.com/sinatra/sinatra/commit/3fe8c38dc405586f7ad8f2ac748aa53e9c3615bd
- github.com/sinatra/sinatra/commit/8ff496bd4877520599e1479d6efead39304edceb
- github.com/sinatra/sinatra/issues/2120
- github.com/sinatra/sinatra/pull/1823
- github.com/sinatra/sinatra/pull/2121
- github.com/sinatra/sinatra/security/advisories/GHSA-mr3q-g2mv-mr4q
- nvd.nist.gov/vuln/detail/CVE-2025-61921
Code Behaviors & Features
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