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Medium · 6.3 CVE-2026-22779 EUVD-2026-2451GHSA-6pw3-h7xf-x4gpPYSEC-2026-1222

BlackSheep ClientSession is vulnerable to CRLF injection

Published Jan 14, 2026 · Updated Jan 14, 2026 · Assigned by GitHub_M

Description

BlackSheep is an asynchronous web framework to build event based web applications with Python. Prior to 2.4.6, the HTTP Client implementation in BlackSheep is vulnerable to CRLF injection. Missing headers validation makes it possible for an attacker to modify the HTTP requests (e.g. insert a new header) or even create a new HTTP request. Exploitation requires developers to pass unsanitized user input directly into headers.The server part is not affected because BlackSheep delegates to an underlying ASGI server handling of response headers. This vulnerability is fixed in 2.4.6.

Affected products

VendorProductAffectedFixed
Neoteroi BlackSheep < 2.4.6 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI blacksheep < 2.4.6 2.4.6 GHSA-6pw3-h7xf-x4gp

References