djangoproject daphne up to 4.2.1 Websocket Handshake splitlines request smuggling

Summaryinfo

A vulnerability was found in djangoproject daphne up to 4.2.1 and classified as problematic. This affects the function splitlines of the component Websocket Handshake Handler. Executing a manipulation can lead to request smuggling. The identification of this vulnerability is CVE-2026-44546. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in djangoproject daphne up to 4.2.1. It has been declared as problematic. This vulnerability affects the function splitlines of the component Websocket Handshake Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality. CVE summarizes:

daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but autobahn decodes header values to str and calls splitlines(). An attacker can exploit this parser differential to inject additional headers into the ASGI scope passed to the application. daphne now rejects requests with these bytes in any header value with a 400 response.

The advisory is available at github.com. This vulnerability was named CVE-2026-44546 since 05/06/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 4.2.2 eliminates this vulnerability. The upgrade is hosted for download at github.com.

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Productinfo

Type

• Content Management System

Vendor

• djangoproject

Name

• daphne

Version

• 4.2.0
• 4.2.1

CPE 2.3info

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CPE 2.2info

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