{"cve":"CVE-2025-61772","nvd":{"published":"2025-10-07T15:16:03.280","modified":"2026-10-19T16:10:00.260","status":"Analyzed","description":"Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, `Rack::Multipart::Parser` can accumulate unbounded data when a multipart part’s header block never terminates with the required blank line (`CRLFCRLF`). The parser keeps appending incoming bytes to memory without a size cap, allowing a remote attacker to exhaust memory and cause a denial of service (DoS). Attackers can send incomplete multipart headers to trigger high memory use, leading to process termination (OOM) or severe slowdown. The effect scales with request size limits and concurrency. All applications handling multipart uploads may be affected. Versions 2.2.19, 3.1.17, and 3.2.2 cap per-part header size (e.g., 64 KiB). As a workaround, restrict maximum request sizes at the proxy or web server layer (e.g., Nginx `client_max_body_size`).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e","https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e","https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd","https://github.com/rack/rack/security/advisories/GHSA-wpv5-97wm-hp9c"],"products":["rack:rack"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2025-61772","score":0.0093,"percentile":0.60345,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wpv5-97wm-hp9c","url":"https://osv.dev/vulnerability/GHSA-wpv5-97wm-hp9c","summary":"Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion)","modified":"2026-09-10T03:50:30.301422073Z","packages":[{"ecosystem":"RubyGems","name":"rack","purl":"pkg:gem/rack","ranges":["<2.2.19"],"fixed":["2.2.19"]},{"ecosystem":"RubyGems","name":"rack","purl":"pkg:gem/rack","ranges":[">=3.1 <3.1.17"],"fixed":["3.1.17"]},{"ecosystem":"RubyGems","name":"rack","purl":"pkg:gem/rack","ranges":[">=3.2 <3.2.2"],"fixed":["3.2.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}