cbcvebase.
CVE-2026-26962
published 2026-04-02

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…

PriorityP336medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
EPSS
0.23%
13.5th percentile
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.

Affected

4 ranges
VendorProductVersion rangeFixed in
debianruby-rack< ruby-rack 3.2.6-2 (sid)ruby-rack 3.2.6-2 (sid)
rackrack
rackrack>= 3.2.0 < 3.2.63.2.6
rackrack>= 3.2.0 < 3.2.63.2.6

CVSS provenance

nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
osv4.8MEDIUM
vendor_debian4.8MEDIUM
vendor_redhat4.8MEDIUM
vendor_ubuntu3.7LOW
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