CVE-2026-85734: lightrag-hku /login endpoint missing rate limiting enables brute-force attacks

CVE-2026-85734 · Severity: critical · CVSS 9.1 · Published 2026-09-22

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.

Technologies: HKUDS LightRAG, lightrag-hku (PyPI). Vendors: HKUDS, PyPI.

Quick answers

Is CVE-2026-85734 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-85734 being exploited in the wild.
How severe is CVE-2026-85734?
Critical severity, with a CVSS score of 9.1, published 22 September 2026.
Which products and versions are affected?
HKUDS LightRAG < 1.5.5; lightrag-hku (PyPI) < 1.5.5, ECOSYSTEM:introduced=0,fixed=1.5.5.
Is there a fix for CVE-2026-85734?
Yes. lightrag-hku (PyPI): upgrade to 1.5.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-85734 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-85734?
Check whether you run HKUDS LightRAG or lightrag-hku (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • lightrag-hku (PyPI): upgrade to 1.5.5 or later
    pip install "lightrag-hku>=1.5.5"

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

Identifiers

  • CVE-2026-85734
  • GHSA-frch-4w6v-q5xx
  • PYSEC-2026-4062

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

References

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