CVE-2026-125108
Received
Received - Intake
Rack Multipart Parser Boundary Bypass Vulnerability
Vulnerability report for CVE-2026-125108, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-09
Last updated on: 2026-11-09
Assigner: GitHub, Inc.
Description
Description
Rack is a modular Ruby web server interface. Prior to 2.2.25, 3.1.23, and 3.2.8, Rack::Multipart::Parser.parse_boundary can skip a leading empty or quoted boundary parameter in a multipart Content-Type header and accept a later parameter. Rack can therefore parse a request body with a boundary that a conforming intermediary would not derive, allowing form fields or file uploads to reach an application without the intended proxy or web application firewall inspection. This issue is fixed in versions 2.2.25, 3.1.23, and 3.2.8.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-436 | Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. |
