rouille up to 3.6.2 Proxy Implementation src/proxy.rs request smuggling

Summaryinfo

A vulnerability, which was classified as problematic, was found in rouille up to 3.6.2. This affects an unknown part of the file src/proxy.rs of the component Proxy Implementation. Such manipulation leads to request smuggling. This vulnerability is traded as CVE-2026-67181. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in rouille up to 3.6.2. Affected by this issue is some unknown functionality of the file src/proxy.rs of the component Proxy Implementation. The manipulation with an unknown input leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. 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. Impacted is integrity. CVE summarizes:

Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize HTTP message boundaries by exploiting improper header forwarding in the proxy implementation. The proxy in src/proxy.rs forwards the client's Transfer-Encoding header to upstream backends unchanged while transmitting a body already de-chunked by tiny_http, enabling CL.TE desynchronization attacks where attackers control where the backend believes the request body ends.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-67181 since 07/28/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/28/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-49890). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• rouille

Version

• 3.6.0
• 3.6.1
• 3.6.2

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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