pyLoad up to 0.5.0b3.dev97 __init__.py set_session_cookie_secure origin validation

Summaryinfo

A vulnerability was found in pyLoad up to 0.5.0b3.dev97. It has been declared as problematic. Affected by this issue is the function set_session_cookie_secure of the file src/pyload/webui/app/__init__.py. Executing a manipulation can lead to origin validation. This vulnerability is handled as CVE-2026-40594. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in pyLoad up to 0.5.0b3.dev97 and classified as problematic. This vulnerability affects the function set_session_cookie_secure of the file src/pyload/webui/app/__init__.py. The manipulation with an unknown input leads to a origin validation vulnerability. The CWE definition for the vulnerability is CWE-346. The product does not properly verify that the source of data or communication is valid. As an impact it is known to affect confidentiality, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-40594 since 04/14/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 0.5.0b3.dev98 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• pyLoad

Version

• 0.5.0b3.dev97

Website

• Product: https://github.com/pyload/pyload/

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