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.
References
Configurations
No configuration.
History
02 Apr 2026, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-02 18:16
Updated : 2026-04-03 16:10
NVD link : CVE-2026-32762
Mitre link : CVE-2026-32762
CVE.ORG link : CVE-2026-32762
JSON object : View
Products Affected
No product.
CWE
CWE-436
Interpretation Conflict
