CVE-2026-40594
Description
pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev98, the set_session_cookie_secure before_request handler in src/pyload/webui/app/__init__.py reads the X-Forwarded-Proto header from any HTTP request without validating that the request originates from a trusted proxy, then mutates the global Flask configuration SESSION_COOKIE_SECURE on every request. Because pyLoad uses the multi-threaded Cheroot WSGI server (request_queue_size=512), this creates a race condition where an attacker's request can influence the Secure flag on other users' session cookies — either downgrading cookie security behind a TLS proxy or causing a session denial-of-service on plain HTTP deployments. This vulnerability is fixed in 0.5.0b3.dev98.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: security-advisories@github.com — https://github.com/pyload/pyload/security/advisories/GHSA-mp82-fmj6-f22v
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| pyload-ng_project | pyload-ng | {"endExcluding":"0.5.0b3.dev69"} | 0.5.0b3.dev69 |
References
CWEs
CWE-346
Verify integrity in audit chain (admin only). AS-IS.