FKIE_CVE-2025-69873

Vulnerability from fkie_nvd - Published: 2026-02-11 19:15 - Updated: 2026-02-12 16:16
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
ajv (Another JSON Schema Validator) through version 8.17.1 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation.
References
cve@mitre.orghttps://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "ajv (Another JSON Schema Validator) through version 8.17.1 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., \"^(a|a)*$\") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation."
    },
    {
      "lang": "es",
      "value": "ajv (Another JSON Schema Validator) hasta la versi\u00f3n 8.17.1 es vulnerable a la denegaci\u00f3n de servicio por expresiones regulares (ReDoS) cuando la opci\u00f3n $data est\u00e1 habilitada. La palabra clave \u0027pattern\u0027 acepta datos en tiempo de ejecuci\u00f3n a trav\u00e9s de la sintaxis JSON Pointer (referencia $data), que se pasa directamente al constructor JavaScript RegExp() sin validaci\u00f3n. Un atacante puede inyectar un patr\u00f3n de expresi\u00f3n regular malicioso (por ejemplo, \u0027^(a|a)*$\u0027) combinado con una entrada manipulada para causar un retroceso catastr\u00f3fico. Una carga \u00fatil de 31 caracteres causa aproximadamente 44 segundos de bloqueo de CPU, y cada car\u00e1cter adicional duplica el tiempo de ejecuci\u00f3n. Esto permite una denegaci\u00f3n de servicio completa con una \u00fanica solicitud HTTP contra cualquier API que utilice ajv con $data: true para la validaci\u00f3n din\u00e1mica de esquemas."
    }
  ],
  "id": "CVE-2025-69873",
  "lastModified": "2026-02-12T16:16:05.583",
  "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-02-11T19:15:50.467",
  "references": [
    {
      "source": "cve@mitre.org",
      "url": "https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}


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