Is CVE-2026-40594 actively exploited?

No active exploitation of CVE-2026-40594 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40594 be exploited remotely?

Yes. CVE-2026-40594 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40594?

CVE-2026-40594 has a CVSS score of 4.8 (MEDIUM).

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MEDIUM

CVE-2026-40594

CWE-346Published: April 21, 2026· Updated: Apr 27, 2026

4.8

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:0.3th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40594 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.