CVE-2025-49007 ReDoS Vulnerability in Rack::Multipart handle_mime_head
Attackers can cause denial of service in Rack-based applications via crafted Content-Disposition headers in multipart requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-49007?
CVE-2025-49007 is a medium-severity denial of service vulnerability in rack, published on 4 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2025-49007?
2 open source packages ship an affected version, including rack. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
rack RubyGems | From 3.1.0 | 3.1.16 |
rack RubyGems | From 3.1.0 | 3.1.16 |
Products include Rack Rack.
How do I fix CVE-2025-49007?
Upgrade rack to 3.1.16 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-49007 being exploited?
There is no known exploitation of CVE-2025-49007 in the wild and no public exploit code.
Other vulnerabilities in rack
- CVE-2026-34785 Rack: Local file inclusion in `Rack::Static` via URL Prefix Matching
- CVE-2026-34827 Rack: Algorithmic-Complexity DoS in Rack::Multipart::Parser
- CVE-2026-34829 Rack: Denial of Service via Unbounded Multipart File Upload Without Content-Length
- CVE-2026-22860 Rack has a Directory Traversal via Rack:Directory
- CVE-2025-61919 Rack is vulnerable to a memory-exhaustion DoS through unbounded URL-encoded body parsing
Sources
Also known as DEBIAN-CVE-2025-49007, GHSA-47m2-26rw-j2jw, MINI-fwgc-fqwr-rc6h.