# CVE-2026-32762: ruby-rack: Rack is a modular Ruby web server interface

CVE-2026-32762 is fixed in ruby-rack on 1 platform, first by ruby-rack 3.2.4-1ubuntu1.1, released April 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-32762
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0019
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 2, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ruby-rack Debian 13.5 (trixie) | 3.1.20-0+deb13u2 | [DEBIAN-CVE-2026-32762](https://patchblox.com/security/data/fix/linux/debian-cve-2026-32762.md) | Apr 2, 2026 |
| Linux | ruby-rack Debian 14 | 3.2.6-2 | [DEBIAN-CVE-2026-32762](https://patchblox.com/security/data/fix/linux/debian-cve-2026-32762.md) | Apr 2, 2026 |
| Linux | ruby-rack Ubuntu 25.10 (questing) | 3.1.16-0.1ubuntu0.3 | [ruby-rack 3.1.16-0.1ubuntu0.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-ruby-rack-3.1.16-0.1ubuntu0.3.md) | Apr 30, 2026 |
| Linux | ruby-rack Ubuntu 26.04.1 LTS (resolute) | 3.2.4-1ubuntu1.1 | [ruby-rack 3.2.4-1ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-ruby-rack-3.2.4-1ubuntu1.1.md) | Apr 2, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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