pyLoad: Session Cookie Security Downgrade via Untrusted X-Forwarded-Proto Header Spoofing (Global State Race Condition)_CVE-2026-40594

{
    "lastseen": "",
    "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 \u2014 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.",
    "published": "2026-04-21T17:14:03.627Z",
    "modified": "2026-04-21T18:01:30.556Z",
    "type": "cve",
    "title": "pyLoad: Session Cookie Security Downgrade via Untrusted X-Forwarded-Proto Header Spoofing (Global State Race Condition)",
    "source": "GitHub_M",
    "references": "https://github.com/pyload/pyload/security/advisories/GHSA-mp82-fmj6-f22v",
    "id": "CVE-2026-40594",
    "bulletinFamily": "",
    "cwe": [
        "CWE-346"
    ],
    "cvelist": null,
    "sourceData": "pyload pyload < 0.5.0b3.dev98",
    "sourceHref": "",
    "cvss": {
        "score": 4.8,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L",
        "version": "3.1"
    },
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    "href": "",
    "category_name": "CVE",
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    "product": "pyload",
    "version": "< 0.5.0b3.dev98",
    "vendor": "pyload",
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}