Rack is a modular Ruby web server interface. Carefully crafted headers can cause header parsing in Rack to take longer than expected resulting in a possible denial of service issue. Accept and Forwarded headers are impacted. Ruby 3.2 has mitigations for this problem, so Rack applications using Ruby 3.2 or newer are unaffected. This vulnerability is fixed in 2.0.9.4, 2.1.4.4, 2.2.8.1, and 3.0.9.1.
https://security.netapp.com/advisory/ntap-20240510-0006/
https://lists.debian.org/debian-lts-announce/2024/04/msg00022.html
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2024-26146.yml
https://github.com/rack/rack/security/advisories/GHSA-54rr-7fvw-6x8f
https://github.com/rack/rack/commit/e4c117749ba24a66f8ec5a08eddf68deeb425ccd
https://github.com/rack/rack/commit/a227cd793778c7c3a827d32808058571569cda6f
https://github.com/rack/rack/commit/6c5d90bdcec0949f7ba06db62fb740dab394b582
https://github.com/rack/rack/commit/30b8e39a578b25d4bdcc082c1c52c6f164b59716