| Name | CVE-2026-125111 |
| Description | Rack is a modular Ruby web server interface. Prior to 2.2.25, 3.1.23, and 3.2.8, Rack::Multipart::Parser can retain parsed data in its internal StringScanner buffer when reads end inside or immediately after multipart headers. An unauthenticated attacker can align many small parts with rack.multipart.buffer_size boundaries so the buffer grows with the request despite per-field, header, and preamble limits, causing a worker to exhaust memory. The attack requires only a well-formed multipart body and affects applications that parse multipart requests. This issue is fixed in versions 2.2.25, 3.1.23, and 3.2.8. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| ruby-rack (PTS) | bookworm | 2.2.22-0+deb12u1 | vulnerable |
| bookworm (security) | 2.2.22-0+deb12u2 | vulnerable | |
| trixie | 3.1.20-0+deb13u1 | vulnerable | |
| trixie (security) | 3.1.20-0+deb13u2 | vulnerable | |
| forky, sid | 3.2.8-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| ruby-rack | source | (unstable) | 3.2.8-1 |
https://github.com/rack/rack/security/advisories/GHSA-5v64-555j-wjxm