CVE-2026-44546: djangoproject daphne HTTP Request/Response Smuggling

Vulnerability summary

CVE-2026-44546 is a medium (CVSS 5.3) HTTP Request/Response Smuggling vulnerability in djangoproject daphne. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20% of scored vulnerabilities.

Timeline

1. 03-06-2026
   PublishedVulnerability first disclosed.
2. 03-06-2026
   Last modifiedVulnerability information updated.

Description

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.

• 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.