{"id":"PYSEC-2026-1222","summary":"BlackSheep's ClientSession is vulnerable to CRLF injection","details":"### Impact\nThe 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.\nExploitation requires developers to pass unsanitized user input directly into headers.\nThe server part is not affected because BlackSheep delegates to an underlying ASGI server handling of response headers.\n\n**Attack vector:** Applications using user input in HTTP client requests (method, URL, headers).\n\n### Patches\nUsers who use the HTTP Client in BlackSheep should upgrade to `2.4.6`.\n\n### Workarounds\nIf users handle headers from untrusted parties, they might reject values for header names and values that contain carriage returns.\n\n### References\nhttps://owasp.org/www-community/vulnerabilities/CRLF_Injection","aliases":["CVE-2026-22779","GHSA-6pw3-h7xf-x4gp"],"modified":"2026-07-07T17:47:32.644648259Z","published":"2026-07-07T16:03:18.908634Z","references":[{"type":"WEB","url":"https://github.com/Neoteroi/BlackSheep/security/advisories/GHSA-6pw3-h7xf-x4gp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-22779"},{"type":"WEB","url":"https://github.com/Neoteroi/BlackSheep/commit/bd4ecb9542b5d52442276b5a6907931b90f38d12"},{"type":"PACKAGE","url":"https://github.com/Neoteroi/BlackSheep"},{"type":"WEB","url":"https://github.com/Neoteroi/BlackSheep/releases/tag/v2.4.6"},{"type":"PACKAGE","url":"https://pypi.org/project/blacksheep"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-6pw3-h7xf-x4gp"}],"affected":[{"package":{"name":"blacksheep","ecosystem":"PyPI","purl":"pkg:pypi/blacksheep"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.6"}]}],"versions":["0.0.1","0.0.2","0.0.4","0.0.5","0.0.6","0.0.7","0.0.9","0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.0.8","1.0.9","1.1.0","1.2.0","1.2.1","1.2.10","1.2.11","1.2.12","1.2.13","1.2.14","1.2.15","1.2.16","1.2.17","1.2.18","1.2.19","1.2.2","1.2.20","1.2.3","1.2.4","1.2.5","1.2.6","1.2.7","1.2.8","1.2.9","2.0.0","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.7","2.0.8","2.0a0","2.0a1","2.0a10","2.0a11","2.0a12","2.0a2","2.0a3","2.0a4","2.0a5","2.0a6","2.0a7","2.0a8","2.0a9","2.1.0","2.2.0","2.3.0","2.3.1","2.3.1a1","2.3.2","2.4.0","2.4.1","2.4.2","2.4.3","2.4.4","2.4.4a0","2.4.4a2","2.4.5"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/blacksheep/PYSEC-2026-1222.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"}]}