CVE-2026-61740 LightRAG is Vulnerable to Authentication Bypass: hardcoded DEFAULT_TOKEN_SECRET and public /auth-status defeat LIGHTRAG_API_KEY protection
Remote attackers can bypass API key authentication in LightRAG to read, modify, or delete documents and query data when specific configuration conditions are met.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-61740?
CVE-2026-61740 is a critical authentication bypass vulnerability in HKUDS LightRAG, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.4, when LightRAG is deployed with LIGHTRAG_API_KEY set but AUTH_ACCOUNTS unset, X-API-Key protection can be bypassed because lightrag/api/auth.py falls back to a hardcoded DEFAULT_TOKEN_SECRET, /auth-status and /login can mint guest JWTs, and combined_dependency in lightrag/api/utils_api.py accepts a valid guest token before checking the API key. A remote unauthenticated attacker can call endpoints guarded by combined_auth, including document read, upload, deletion, graph mutation, and query endpoints. This vulnerability is fixed in 1.5.4.
Which versions are affected by CVE-2026-61740?
3 open source packages ship an affected version, including lightrag-hku.
| Package | Affected | Fixed in |
|---|---|---|
lightrag-hku PyPI | All versions | 1.5.4 |
lightrag-hku PyPI | All versions | 1.5.4 |
lightrag-hku PyPI | All versions | 1.5.4 |
How do I fix CVE-2026-61740?
Upgrade lightrag-hku to 1.5.4 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-61740 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61740 exists.
Sources
Also known as GHSA-f4vv-55c2-5789, PYSEC-2026-3475.