CVE-2026-61736 is a critical vulnerability in HKUDS LightRAG where, before version 1.5.4, the server defaults to CORS_ORIGINS=* combined with allow_credentials=True in the lightrag/api/lightrag_server.py file. This configuration causes the Starlette CORSMiddleware to whitelist all origins for credentialed cross-origin requests, effectively allowing any website visited by an authenticated user to silently make authenticated API requests. Exploitation can lead to exfiltration of sensitive documents and knowledge graph data or destructive actions such as deleting the document store. The issue is addressed in LightRAG version 1.5.4.

An attacker controlling a malicious website can exploit this vulnerability by tricking an authenticated LightRAG user into visiting the site, enabling the attacker to perform unauthorized API requests with the user's credentials. This can result in high confidentiality and integrity impact, including data theft and deletion of critical data stores. Availability impact is not indicated.

Upgrade LightRAG to version 1.5.4 or later, where the default CORS configuration is corrected to prevent credentialed cross-origin requests from all origins. Since no official patch link or advisory is provided, verify the upgrade path with the vendor or official repositories. Until upgraded, restrict CORS_ORIGINS to trusted domains and avoid allowing credentials with wildcard origins.