---
title: "CVE-2026-85734: lightrag-hku: No Rate Limiting on /login Endpoint Allows Brute-Force Attacks"
url: https://erroneo.us/security/cve/CVE-2026-85734/
description: "CVE-2026-85734 (lightrag-hku (PyPI)): LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, the POST /login endpoint in…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-22
date_modified: 2026-09-22
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-85734"
kev: false
cvss: 9.1
epss: 0.00355
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-85734: lightrag-hku: No Rate Limiting on /login Endpoint Allows Brute-Force Attacks

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4% , percentile 28: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 28% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes lightrag-hku (PyPI) < 1.5.5, fixed in 1.5.5 . Check your lockfile, including transitive dependencies.

## What it is

LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, the POST /login endpoint in lightrag/api/lightragserver.py does not impose a rate limit, account lockout, delay, or counter for failed authentication attempts. A network attacker can submit password guesses at full request speed until a valid account password is found. Successful credential recovery grants authenticated access to documents, the knowledge graph, and administrative operations. This issue is fixed in version 1.5.5.

## Affected packages

- PyPI `lightrag-hku` < 1.5.5 → fixed: 1.5.5

## Affected products (CVE record)

- HKUDS LightRAG: < 1.5.5

## Severity

- GitHub_M CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.36% probability of exploitation activity in the next 30 days; percentile 28.

## Sources

- [GitHub Advisory GHSA-frch-4w6v-q5xx](https://github.com/advisories/GHSA-frch-4w6v-q5xx)
- [CVE.org record CVE-2026-85734](https://www.cve.org/CVERecord?id=CVE-2026-85734)
- [NVD entry CVE-2026-85734](https://nvd.nist.gov/vuln/detail/CVE-2026-85734)
- [github.com](https://github.com/HKUDS/LightRAG/security/advisories/GHSA-frch-4w6v-q5xx)
- [github.com](https://github.com/HKUDS/LightRAG/pull/3424)
- [github.com](https://github.com/HKUDS/LightRAG/commit/135bc9056e9ecd800c1abe2f2ce24d1a86622a54)
- [github.com](https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5)

---
Source page: https://erroneo.us/security/cve/CVE-2026-85734/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt