CVE-2025-49007
ReDoS Vulnerability in Rack::Multipart handle_mime_head
CVE-2025-49007 is a medium vulnerability (CVSS 6.6) in Rack, published June 4, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.58%, the 47th percentile. Fixed in rack 3.1.16.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
6.6
ReDoS Vulnerability in Rack::Multipart handle_mime_head
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.
- Record
CVE-2025-49007- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2025-16936
6.6
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.
- Record
EUVD-2025-16936- CVSS 4.0
- 6.6 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-47m2-26rw-j2jw
6.6
ReDoS Vulnerability in Rack::Multipart handle_mime_head
Summary
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.
Details
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.
Credits
Thanks to scyoon for reporting this to the Rails security team
- Record
GHSA-47m2-26rw-j2jw- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
6.6
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.
- Record
CVE-2025-49007- CVSS 4.0
- 6.6 Medium
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-770, CWE-1333
- Updated
- 2026-11-02
OSV
6.6
ReDoS Vulnerability in Rack::Multipart handle_mime_head
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.
- Record
CVE-2025-49007- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2025-49007
5.3
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.
- Record
DEBIAN-CVE-2025-49007- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVGHSA-47m2-26rw-j2jw
6.6
ReDoS Vulnerability in Rack::Multipart handle_mime_head
Summary
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.
Details
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.
Credits
Thanks to scyoon for reporting this to the Rails security team
- Record
GHSA-47m2-26rw-j2jw- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-49007
6.6
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.
- Record
UBUNTU-CVE-2025-49007- CVSS 4.0
- 6.6 Medium
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 - Updated
- 2026-11-02
OSVMGASA-2025-0334 No score
Updated ruby-rack packages fix security vulnerabilities
Unbounded-Parameter DoS in Rack::QueryParser. (CVE-2025-46727) ReDoS Vulnerability in Rack::Multipart handle_mime_head. (CVE-2025-49007) Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters. (CVE-2025-59830) Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion). (CVE-2025-61770) Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion). (CVE-2025-61771) Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion). (CVE-2025-61772) Rack is vulnerable to a memory-exhaustion DoS through unbounded URL-encoded body parsing. (CVE-2025-61919) Rack has Possible Information Disclosure Vulnerability. (CVE-2025-61780)
- Record
MGASA-2025-0334- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rackRubyGems |
3.1.0 up to 3.1.16 | 3.1.16 |
ruby-rackDebian:13 |
before 3.1.16-0.1 | 3.1.16-0.1 |
ruby-rackDebian:14 |
before 3.1.16-0.1 | 3.1.16-0.1 |
rackRubyGems |
3.1.0 up to 3.1.16, plus listed versions 3.1.13.1.103.1.113.1.123.1.13 Show 10 moreShow less3.1.143.1.153.1.23.1.33.1.43.1.53.1.63.1.73.1.83.1.9 |
3.1.16 |
ruby-rackMageia:9 |
before 2.2.21-1.mga9 | 2.2.21-1.mga9 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | affected | |
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |
References
github.com/rack/rack/security/advisories/GHSA-47m2-26rw-j2jw
github.com/rack/rack/commit/4795831a0a310c2d31102749e551b38faab6401f
github.com/rack/rack/commit/aed514df37e33907df3c971ed3ca9a0a20ac2901
nvd.nist.gov/vuln/detail/CVE-2025-49007
github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-49007.yml
github.com/advisories/GHSA-47m2-26rw-j2jw
Show 8 moreShow less
github.com/CVEProject/cvelistV5/tree/main/cves/2025/49xxx/CVE-2025-49007.json
security-tracker.debian.org/tracker/CVE-2025-49007
github.com/rack/rack
advisories.mageia.org/MGASA-2025-0334.html
bugs.mageia.org/show_bug.cgi?id=34755
rack.github.io/rack/3.2/CHANGELOG_md.html
ubuntu.com/security/CVE-2025-49007
cve.org/CVERecord?id=CVE-2025-49007