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 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 products

Linuxmint, Rack, Ubuntu

Rack

< 3.1.21, 3.2.6

Fix

Available

CVSS 3.1

6.5 MEDIUM

EPSS

0.2% (8th percentile)

Weakness

CWE-436

NVD status

Analyzed

Published

2026-04-02

No exploit for CVE-2026-32762 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.