CVE-2026-67182: tomaka rouille HTTP Request/Response Smuggling

Vulnerability summary

CVE-2026-67182 is a high (CVSS 7.5) HTTP Request/Response Smuggling vulnerability in tomaka rouille. EPSS estimates a 0.63% chance of exploitation in the next 30 days, higher than 49.4% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 28-07-2026
   PublishedVulnerability first disclosed.
2. 28-07-2026
   Last modifiedVulnerability information updated.

Description

Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to bypass access controls by injecting bare line feed characters (0x0A) into client-supplied request header values that are copied verbatim to upstream connections without validation. Attackers can craft a header value containing a complete additional HTTP request that is interpreted as a separate request by backends such as Go net/http and Python http.server, causing the backend to process a smuggled request with attacker-chosen method, path, and headers that bypasses the rouille handler's access control logic.

• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.