CVE-2026-42860: Open edx Enterprise Service: SSRF via SAML metadata URL in sync_provider_data endpoint

The Open edx Enterprise Service app provides enterprise features to the Open edX platform. From 7.0.2 to 7.0.4, the sync_provider_data endpoint in SAMLProviderDataViewSet fetches SAML metadata from a URL stored in SAMLProviderConfig.metadata_source. An authenticated user with the Enterprise Admin role can set this field to an arbitrary URL via the SAMLProviderConfigViewSet PATCH endpoint, then trigger a server-side HTTP request by calling sync_provider_data. The fetch in fetch_metadata_xml() passes the URL directly to requests.get() with no scheme enforcement, IP filtering, or timeout. This vulnerability is fixed in 7.0.5.