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.
References (3)
Scores
CVSS v3
5.3
EPSS
0.0004
EPSS Percentile
12.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-113
Status
published
Products (2)
neoteroi/blacksheep
< 2.4.6
pypi/blacksheep
0 - 2.4.6PyPI
Published
Jan 14, 2026
Tracked Since
Feb 18, 2026