CVE-2026-26962

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename or name instead of removing the folded line break during unfolding. As a result, applications that later reuse those parsed values in HTTP response headers may be vulnerable to downstream header injection or response splitting. This issue has been patched in version 3.2.6.

CVSS v3 4.8 MEDIUM

4.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv	Vendor Advisory Mitigation

Configurations

Configuration 1 (hide)

cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*

History

21 Apr 2026, 00:42

Type	Values Removed	Values Added
First Time		Rack rack Rack
References	~~() https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv -~~	() https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv - Vendor Advisory, Mitigation
CPE		cpe:2.3:a:rack:rack::::::ruby::*

02 Apr 2026, 18:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-02 18:16

Updated : 2026-04-21 00:42

NVD link : CVE-2026-26962

Mitre link : CVE-2026-26962

CVE.ORG link : CVE-2026-26962

JSON object : View

Products Affected

rack

rack

CWE

CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')

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