PT-2026-29841 · Rack · Rack

Wtn · Published 2026-04-02 · Updated 2026-04-02 · CVE-2026-26962

NVD

CVSS v3.1

4.8

Medium

AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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.

Fix

Weakness Enumeration

CWE-93

Related Identifiers

CVE-2026-26962

Affected Products

Rack

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-26962 · Security Note
• https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv · Note