{"id":"PYSEC-2026-2998","summary":"pyLoad Has Incomplete Fix for CVE-2026-33509 -storage_folder Bypass via Session Directory in pyLoad","details":"## Summary\nThe fix for CVE-2026-33509 prevents setting `storage_folder` inside `PKGDIR` or `userdir`, but does NOT protect the Flask session directory (`/tmp/pyLoad/flask`). An authenticated attacker can set `storage_folder` to the session directory and download session files of other users via `/files/get/`, leading to account takeover.\n\n## Details\n\nThe fix in `src/pyload/core/api/__init__.py`:\n\n```python\ndirectories = [PKGDIR, userdir]\nif any(directories[0].startswith(d) for d in directories[1:]):\n    return  # blocked\n```\n\nBut the Flask session directory is:\n```python\nsession_storage_path = os.path.join(api.get_cachedir(), \"flask\")\n# = /tmp/pyLoad/flask  ← NOT blocked by fix\n```\n\n## Attack Chain\n\n1. Attacker (admin) sets `storage_folder = /tmp/pyLoad/flask`\n2. Fix does NOT block this — `/tmp/pyLoad/flask` not inside `PKGDIR` or `userdir`\n3. Attacker requests `GET /files/get/\u003cvictim_session_filename\u003e`\n4. `send_from_directory('/tmp/pyLoad/flask', session_file)` serves victim's session\n5. Attacker uses stolen session → **Account Takeover**\n\n## PoC\n\n\u003cimg width=\"592\" height=\"408\" alt=\"POC\" src=\"https://github.com/user-attachments/assets/936b9f56-325b-437d-9edd-e0d5bb995187\" /\u003e\n\n```python\nimport os\n\nPKGDIR = \"/usr/lib/python3/dist-packages/pyload\"\nuserdir = os.path.expanduser(\"~/.pyload\")\nsession_dir = \"/tmp/pyLoad/flask\"\n\ncorrect_case = lambda x: x\ndirectories = [\n    correct_case(os.path.join(os.path.realpath(d), \"\"))\n    for d in [session_dir, PKGDIR, userdir]\n]\nblocked = any(directories[0].startswith(d) for d in directories[1:])\n\nprint(f\"Fix blocks session_dir: {blocked}\")\n# Output: Fix blocks session_dir: False  ← BYPASS CONFIRMED\n```\n\n## Impact\nAuthenticated admin can steal sessions of other users → Account Takeover.\n\n## Suggested Fix\n```python\nblocked_dirs = [PKGDIR, userdir, api.get_cachedir()]\ndirectories = [\n    os.path.join(os.path.realpath(d), \"\")\n    for d in [value] + blocked_dirs\n]\nif any(directories[0].startswith(d) for d in directories[1:]):\n    return\n```","aliases":["CVE-2026-45306","GHSA-w727-595x-pc3r"],"modified":"2026-07-13T16:32:43.930902604Z","published":"2026-07-13T15:19:05.979484Z","references":[{"type":"WEB","url":"https://github.com/pyload/pyload/security/advisories/GHSA-w727-595x-pc3r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45306"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-r7mc-x6x7-cqxx"},{"type":"PACKAGE","url":"https://github.com/pyload/pyload"},{"type":"PACKAGE","url":"https://pypi.org/project/pyload-ng"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-w727-595x-pc3r"}],"affected":[{"package":{"name":"pyload-ng","ecosystem":"PyPI","purl":"pkg:pypi/pyload-ng"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.5.0b3.dev99"}]}],"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","0.5.0b3.dev89","0.5.0b3.dev90","0.5.0b3.dev91","0.5.0b3.dev92","0.5.0b3.dev93","0.5.0b3.dev94","0.5.0b3.dev95","0.5.0b3.dev96","0.5.0b3.dev97","0.5.0b3.dev98","0.5.0b3.dev99"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/pyload-ng/PYSEC-2026-2998.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N"}]}