FKIE_CVE-2024-58340

Vulnerability from fkie_nvd - Published: 2026-01-12 23:15 - Updated: 2026-01-21 17:57
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
LangChain versions up to and including 0.3.1 contain a regular expression denial-of-service (ReDoS) vulnerability in the MRKLOutputParser.parse() method (libs/langchain/langchain/agents/mrkl/output_parser.py). The parser applies a backtracking-prone regular expression when extracting tool actions from model output. An attacker who can supply or influence the parsed text (for example via prompt injection in downstream applications that pass LLM output directly into MRKLOutputParser.parse()) can trigger excessive CPU consumption by providing a crafted payload, causing significant parsing delays and a denial-of-service condition.
References
disclosure@vulncheck.comhttps://github.com/langchain-ai/langchainProduct
disclosure@vulncheck.comhttps://huntr.com/bounties/e7ece02c-d4bb-4166-8e08-6baf4f8845bbExploit, Issue Tracking, Third Party Advisory
disclosure@vulncheck.comhttps://www.langchain.com/Product
disclosure@vulncheck.comhttps://www.vulncheck.com/advisories/langchain-mrkloutputparser-redosThird Party Advisory
Impacted products
Vendor Product Version
langchain langchain *
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{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:langchain:langchain:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6E9D0E05-1453-4F45-BA4F-C188E1639974",
              "versionEndIncluding": "0.3.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "LangChain versions up to and including 0.3.1 contain a regular expression denial-of-service (ReDoS) vulnerability in the MRKLOutputParser.parse() method (libs/langchain/langchain/agents/mrkl/output_parser.py). The parser applies a backtracking-prone regular expression when extracting tool actions from model output. An attacker who can supply or influence the parsed text (for example via prompt injection in downstream applications that pass LLM output directly into MRKLOutputParser.parse()) can trigger excessive CPU consumption by providing a crafted payload, causing significant parsing delays and a denial-of-service condition."
    },
    {
      "lang": "es",
      "value": "Las versiones de LangChain hasta la 0.3.1 inclusive contienen una vulnerabilidad de denegaci\u00f3n de servicio por expresi\u00f3n regular (ReDoS) en el m\u00e9todo MRKLOutputParser.parse() (libs/langchain/langchain/agents/mrkl/output_parser.py). El analizador aplica una expresi\u00f3n regular propensa a retrocesos al extraer acciones de herramientas de la salida del modelo. Un atacante que puede suministrar o influir en el texto analizado (por ejemplo, mediante inyecci\u00f3n de prompt en aplicaciones posteriores que pasan la salida del LLM directamente a MRKLOutputParser.parse()) puede desencadenar un consumo excesivo de CPU al proporcionar una carga \u00fatil manipulada, causando retrasos significativos en el an\u00e1lisis y una condici\u00f3n de denegaci\u00f3n de servicio."
    }
  ],
  "id": "CVE-2024-58340",
  "lastModified": "2026-01-21T17:57:56.537",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-12T23:15:51.780",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/langchain-ai/langchain"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "url": "https://huntr.com/bounties/e7ece02c-d4bb-4166-8e08-6baf4f8845bb"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Product"
      ],
      "url": "https://www.langchain.com/"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.vulncheck.com/advisories/langchain-mrkloutputparser-redos"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}


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