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CVE-2026-72691

Estado: AplazadaAlta (7.5)—

An authentication bypass vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to mint MASTER_KEY-signed file access tokens for arbitrary stored files via the getsignedurl Parse cloud function. The function skips its isAuthenticated check whenever any docId parameter is supplied, even one corresponding to no real document, allowing the authentication gate to be bypassed by supplying an arbitrary string as docId.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N indica explotación remota sin autenticación (T1190). El bypass de autenticación permite mintear tokens de acceso para archivos arbitrarios, otorgando acceso a recursos (T1078). La capacidad de obtener URLs firmadas implica lectura de datos almacenados (T1005).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementApplication Developer GuidanceActive Directory ConfigurationVulnerability ScanningUser TrainingUser Account Management

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Opensignlabs — OpensignserverAI

CWE

Referencias

JSON original (NVD)

Mostrar
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  "id": "CVE-2026-72691",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-72691",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-10T15:37:46.009148Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
      "affectedData": [
        {
          "vendor": "OpenSignLabs",
          "product": "opensignserver",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "2.37.0"
            }
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          "defaultStatus": "affected"
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  ],
  "published": "2026-08-10T13:20:39.350",
  "references": [
    {
      "url": "https://github.com/OpenSignLabs/OpenSign",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
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      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
      "description": [
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    {
      "lang": "en",
      "value": "An authentication bypass vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to mint MASTER_KEY-signed file access tokens for arbitrary stored files via the getsignedurl Parse cloud function. The function skips its isAuthenticated check whenever any docId parameter is supplied, even one corresponding to no real document, allowing the authentication gate to be bypassed by supplying an arbitrary string as docId."
    }
  ],
  "lastModified": "2026-08-26T17:36:16.900",
  "sourceIdentifier": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
}