{"id":"PYSEC-2026-1822","summary":"pyLoad is vulnerable to attacks that bypass localhost restrictions, enabling the creation of arbitrary packages","details":"### Summary\nAny unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages.\n\n### Details\nAny unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages. This is done by changing the `Host` header to the value of `127.0.0.1:9666`.\n\n### PoC\nThe application has middleware that prevents access to several routes by checking whether the `Host` header has a specific value. We bypassed this restriction.\n\nhttps://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L21-L36\n```python\n#: decorator\ndef local_check(func):\n    @wraps(func)\n    def wrapper(*args, **kwargs):\n        remote_addr = flask.request.environ.get(\"REMOTE_ADDR\", \"0\")\n        http_host = flask.request.environ.get(\"HTTP_HOST\", \"0\")\n\n        if remote_addr in (\"127.0.0.1\", \"::ffff:127.0.0.1\", \"::1\", \"localhost\") or http_host in (\n            \"127.0.0.1:9666\",\n            \"[::1]:9666\",\n        ):\n            return func(*args, **kwargs)\n        else:\n            return \"Forbidden\", 403\n\n    return wrapper\n```\n\nBelow we see that the '/flash/add' endpoint uses the middleware above.\n\nhttps://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L56-L58C11\n```python\n@bp.route(\"/flash/add\", methods=[\"POST\"], endpoint=\"add\")\n@local_check\ndef add():\n```\n\nNotice how we are not authorized to access this endpoint when sending a request.\n![image](https://user-images.githubusercontent.com/44903767/294935526-64217d91-c0d1-4d8f-963f-cedfa8dc9034.png)\n\nHowever, if we set the `Host` header to be `127.0.0.1:9666`, we notice the request returns `success`.\n![image](https://user-images.githubusercontent.com/44903767/294933755-43ad3826-0e94-4ba5-acf0-48f11670cbc6.png)\n\nChecking the front end as an admin, we now see that this did indeed succeed.\n![image](https://user-images.githubusercontent.com/44903767/294934431-5d024c75-59dc-47b6-8887-b14ae91e320f.png)\n\n### Impact\nAn unauthenticated user can perform actions that should only be available to authenticated users.","aliases":["CVE-2025-7346","GHSA-x698-5hjm-w2m5"],"modified":"2026-07-07T17:47:50.494251877Z","published":"2026-07-07T16:02:57.423411Z","references":[{"type":"WEB","url":"https://github.com/pyload/pyload/security/advisories/GHSA-x698-5hjm-w2m5"},{"type":"WEB","url":"https://github.com/pyload/pyload/commit/f4e2d12416ba2dfac7b036d5c8d6dab5461b9840"},{"type":"PACKAGE","url":"https://github.com/pyload/pyload"},{"type":"WEB","url":"https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L21-L36"},{"type":"WEB","url":"https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L56-L58C11"},{"type":"PACKAGE","url":"https://pypi.org/project/pyload-ng"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-x698-5hjm-w2m5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-7346"}],"affected":[{"package":{"name":"pyload-ng","ecosystem":"PyPI","purl":"pkg:pypi/pyload-ng"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.5.0b3.dev88"}]}],"versions":["0.5.0a5.dev528","0.5.0a5.dev532","0.5.0a5.dev535","0.5.0a5.dev536","0.5.0a5.dev537","0.5.0a5.dev539","0.5.0a5.dev540","0.5.0a5.dev545","0.5.0a5.dev562","0.5.0a5.dev564","0.5.0a5.dev565","0.5.0a6.dev570","0.5.0a6.dev578","0.5.0a6.dev587","0.5.0a7.dev596","0.5.0a8.dev602","0.5.0a9.dev615","0.5.0a9.dev629","0.5.0a9.dev632","0.5.0a9.dev641","0.5.0a9.dev643","0.5.0a9.dev655","0.5.0a9.dev806","0.5.0b1.dev1","0.5.0b1.dev2","0.5.0b1.dev3","0.5.0b1.dev4","0.5.0b1.dev5","0.5.0b2.dev10","0.5.0b2.dev11","0.5.0b2.dev12","0.5.0b2.dev9","0.5.0b3.dev13","0.5.0b3.dev14","0.5.0b3.dev17","0.5.0b3.dev18","0.5.0b3.dev19","0.5.0b3.dev20","0.5.0b3.dev21","0.5.0b3.dev22","0.5.0b3.dev24","0.5.0b3.dev26","0.5.0b3.dev27","0.5.0b3.dev28","0.5.0b3.dev29","0.5.0b3.dev30","0.5.0b3.dev31","0.5.0b3.dev32","0.5.0b3.dev33","0.5.0b3.dev34","0.5.0b3.dev35","0.5.0b3.dev38","0.5.0b3.dev39","0.5.0b3.dev40","0.5.0b3.dev41","0.5.0b3.dev42","0.5.0b3.dev43","0.5.0b3.dev44","0.5.0b3.dev45","0.5.0b3.dev46","0.5.0b3.dev47","0.5.0b3.dev48","0.5.0b3.dev49","0.5.0b3.dev50","0.5.0b3.dev51","0.5.0b3.dev52","0.5.0b3.dev53","0.5.0b3.dev54","0.5.0b3.dev57","0.5.0b3.dev60","0.5.0b3.dev62","0.5.0b3.dev64","0.5.0b3.dev65","0.5.0b3.dev66","0.5.0b3.dev67","0.5.0b3.dev68","0.5.0b3.dev69","0.5.0b3.dev70","0.5.0b3.dev71","0.5.0b3.dev72","0.5.0b3.dev73","0.5.0b3.dev74","0.5.0b3.dev75","0.5.0b3.dev76","0.5.0b3.dev77","0.5.0b3.dev78","0.5.0b3.dev79","0.5.0b3.dev80","0.5.0b3.dev81","0.5.0b3.dev82","0.5.0b3.dev85","0.5.0b3.dev87","0.5.0b3.dev88"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/pyload-ng/PYSEC-2026-1822.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}