CVE-2025-61770

A flaw was found in Rack where the Rack::Multipart::Parser buffers the multipart preamble memory without size limits. A remote attacker can send a crafted multipart/form-data request with a very large preamble before its first boundary, causing excessive memory consumption and denial of service crash due to out-of-memory issue.

This is IMPORTANT because the vulnerability can be exploited over a network and can cause denial of service on such applications that run the vulnerable Rack code. By sending multipart requests with large preambles, an attacker can exhaust memory resources or crash worker processes, leading to service downtime.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.