{"cve":"CVE-2026-40594","nvd":{"published":"2026-04-21T18:16:51.553","modified":"2026-06-17T10:45:30.287","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L","score":4.8},"cwes":["CWE-346"],"references":["https://github.com/pyload/pyload/security/advisories/GHSA-mp82-fmj6-f22v","https://github.com/pyload/pyload/security/advisories/GHSA-mp82-fmj6-f22v"],"products":["pyload-ng_project:pyload-ng"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-40594","score":0.00171,"percentile":0.06439,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-mp82-fmj6-f22v","url":"https://osv.dev/vulnerability/GHSA-mp82-fmj6-f22v","summary":"pyLoad has a Session Cookie Security Downgrade via Untrusted X-Forwarded-Proto Header Spoofing (Global State Race Condition)","modified":"2026-06-08T20:00:10.592523161Z","packages":[{"ecosystem":"PyPI","name":"pyload-ng","purl":"pkg:pypi/pyload-ng","ranges":["<0.5.0b3.dev98"],"fixed":["0.5.0b3.dev98"]}]},{"id":"PYSEC-2026-125","url":"https://osv.dev/vulnerability/PYSEC-2026-125","summary":"","modified":"2026-05-20T09:19:15.897854Z","packages":[{"ecosystem":"PyPI","name":"pyload-ng","purl":"pkg:pypi/pyload-ng","ranges":["<0.5.0b3.dev69"],"fixed":["0.5.0b3.dev69"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}