PT-2026-2972 · Pypi · Blacksheep

Published 2026-01-14 · Updated 2026-01-14

OSV

CVSS v4.0

6.3

Medium

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Impact

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.

Attack vector: Applications using user input in HTTP client requests (method, URL, headers).

Patches

Users who use the HTTP Client in BlackSheep should upgrade to 2.4.6.

Workarounds

If users handle headers from untrusted parties, they might reject values for header names and values that contain carriage returns.

References

https://owasp.org/www-community/vulnerabilities/CRLF Injection

Fix

Weakness Enumeration

CWE-93

CWE-113

Related Identifiers

GHSA-6PW3-H7XF-X4GP

Affected Products

Blacksheep

References · 6

• https://osv.dev/vulnerability/GHSA-6pw3-h7xf-x4gp · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-22779 · Security Note
• https://github.com/Neoteroi/BlackSheep/security/advisories/GHSA-6pw3-h7xf-x4gp · Note
• https://github.com/Neoteroi/BlackSheep/commit/bd4ecb9542b5d52442276b5a6907931b90f38d12 · Note
• https://github.com/Neoteroi/BlackSheep/releases/tag/v2.4.6 · Note
• https://github.com/Neoteroi/BlackSheep · Note