CVE-2026-32762
rack: Rack: Parameter smuggling via improper Forwarded header parsing
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 3, 2026
Updated · June 30, 2026
Description
A flaw was found in Rack, a modular Ruby web server interface. This vulnerability arises from improper parsing of the RFC 7239 Forwarded header, where semicolons within quoted values are incorrectly interpreted as delimiters. An attacker can exploit this by crafting a malicious Forwarded header, potentially leading to the smuggling of host, protocol, or other parameters. This could allow for spoofing or bypassing security measures in deployments utilizing upstream proxies, Web Application Firewalls (WAFs), or other intermediaries.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CWE-115 · Misinterpretation of Input