cbcvebase.
CVE-2026-32762
published 2026-04-02

CVE-2026-32762: Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21 and 3.2.0 to before 3.2.6, Rack::Utils.forwarded_values parses the RFC…

PriorityP335medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
EPSS
0.18%
7.7th percentile
Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21 and 3.2.0 to before 3.2.6, Rack::Utils.forwarded_values parses the RFC 7239 Forwarded header by splitting on semicolons before handling quoted-string values. Because quoted values may legally contain semicolons, a header can be interpreted by Rack as multiple Forwarded directives rather than as a single quoted for value. In deployments where an upstream proxy, WAF, or intermediary validates or preserves quoted Forwarded values differently, this discrepancy can allow an attacker to smuggle host, proto, for, or by parameters through a single header value. This issue has been patched in versions 3.1.21 and 3.2.6.

Affected

7 ranges
VendorProductVersion rangeFixed in
debianruby-rack< ruby-rack 3.2.6-2 (sid)ruby-rack 3.2.6-2 (sid)
rackrack
rackrack
rackrack>= 3.0.0 < 3.1.213.1.21
rackrack>= 3.0.0.beta1 < 3.1.213.1.21
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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