Executive brief
LightRAG is a knowledge graph and document management system. The login endpoint lacks rate limiting or account lockout protections, allowing attackers on the network to try unlimited password guesses at full speed. Successful compromise grants full access to all stored documents, the knowledge graph, and administrative functions.
Technical details
The vulnerability is improper restriction of excessive authentication attempts (CWE-307). The POST /login endpoint in lightrag/api/lightrag_server.py performs password verification but implements no rate limiting, lockout mechanism, backoff delay, CAPTCHA, or attempt counter. An unauthenticated attacker can send unlimited login requests over the network without any throttling. By brute-forcing the endpoint with a common password wordlist, an attacker can recover valid credentials and gain full authenticated access to the system. The vulnerability was patched in version 1.5.5.
Affected products
- HKUDS LightRAG < 1.5.5
Timeline
- 2026-07-18: disclosed: GitHub advisory published
- 2026-09-22: patched: Version 1.5.5 released with fix
- 2026-09-22: advisory: CVE-2026-85734 and GHSA-frch-4w6v-q5xx published