theopaid rouille up to 3.6.2 response splitting

Summaryinfo

A vulnerability was found in theopaid rouille up to 3.6.2. It has been rated as critical. This issue affects some unknown processing. The manipulation leads to response splitting. This vulnerability is referenced as CVE-2026-66746. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in theopaid rouille up to 3.6.2. This issue affects an unknown function. The manipulation with an unknown input leads to a response splitting vulnerability. Using CWE to declare the problem leads to CWE-113. The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Rouille 0.4.0 through 3.6.2 contains an HTTP response splitting vulnerability that allows remote attackers to inject arbitrary response headers by embedding carriage return (0x0D) or line feed (0x0A) bytes into attacker-controlled input. Attackers can exploit percent-decoded query parameters reflected into response headers or inject bare LF characters into Cookie header values that are interpolated directly into Set-Cookie response headers, enabling cache poisoning, session fixation, and security header override attacks such as bypassing CSP or CORS policies.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-66746 since 07/27/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (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.

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Productinfo

Vendor

• theopaid

Name

• rouille

Version

• 3.6.0
• 3.6.1
• 3.6.2

CPE 2.3info

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CPE 2.2info

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