CVE-2025-49007
ReDoS Vulnerability in Rack::Multipart handle_mime_head
Description
Rack is a modular Ruby web server interface. Starting in version 3.1.0 and prior to version 3.1.16, there is a denial of service vulnerability in the Content-Disposition parsing component of Rack. This is very similar to the previous security issue CVE-2022-44571. Carefully crafted input can cause Content-Disposition header parsing in Rack to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is used typically used in multipart parsing. Any applications that parse multipart posts using Rack (virtually all Rails applications) are impacted. Version 3.1.16 contains a patch for the vulnerability.
How to fix CVE-2025-49007
To remediate CVE-2025-49007, upgrade the affected package to a fixed version below.
- —upgrade to 3.1.16-0.1 or later
- —upgrade to 3.1.16 or later
Is CVE-2025-49007 being exploited?
Low — EPSS is 0.6%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 3.1.16-0.1
- >= 3.1.0, < 3.1.16
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |