CVE-2026-74941

Estado: AnalizadaAlta (8.8)—

Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Puntuación base: 8.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.48%
Percentil entre todas las CVEs puntuadas: 40
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1203 Exploitation for Client Executionexecution95 %
Impacto principalT1068 Exploitation for Privilege Escalationprivilege escalation90 %

UI:R y acceso remoto sin privilegios indican explotación en el cliente (T1203). CWE-269 (improper access control) en componente gráfico permite escalada de privilegios local tras la ejecución.

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

Application Isolation and Sandboxing Exploit Protection Update Software Threat Intelligence Program Execution Prevention

Tecnologías afectadas (2)

Mozilla — Firefox Mozilla — Thunderbird

CWE

CWE-269

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-74941",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74941",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-20T00:00:00+00:00"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "security@mozilla.org",
      "affectedData": [
        {
          "vendor": "Mozilla",
          "product": "Firefox",
          "versions": [
            {
              "status": "unaffected",
              "version": "140.14",
              "versionType": "rpm",
              "lessThanOrEqual": "140.*"
            },
            {
              "status": "unaffected",
              "version": "153.1",
              "versionType": "rpm",
              "lessThanOrEqual": "153.*"
            },
            {
              "status": "unaffected",
              "version": "154",
              "versionType": "rpm",
              "lessThanOrEqual": "*"
            }
          ]
        },
        {
          "vendor": "Mozilla",
          "product": "Thunderbird",
          "versions": [
            {
              "status": "unaffected",
              "version": "140.14",
              "versionType": "rpm",
              "lessThanOrEqual": "140.*"
            },
            {
              "status": "unaffected",
              "version": "153.1",
              "versionType": "rpm",
              "lessThanOrEqual": "153.*"
            },
            {
              "status": "unaffected",
              "version": "154",
              "versionType": "rpm",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-08-18T13:17:30.513",
  "references": [
    {
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2055056",
      "tags": [
        "Permissions Required"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-74/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-76/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-77/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-78/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-79/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-80/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@mozilla.org"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "description": [
        {
          "lang": "en",
          "value": "CWE-269"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."
    }
  ],
  "lastModified": "2026-08-21T04:18:17.047",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4104BED1-BF78-4E44-9721-C69C07284BB5",
              "versionEndExcluding": "140.14.0"
            },
            {
              "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "12575D57-0051-4902-907D-56C351EED221",
              "versionEndExcluding": "153.1.0",
              "versionStartIncluding": "141.0.0"
            },
            {
              "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4E2EC2AA-23B2-45C9-8594-DF80A0D800A7",
              "versionEndExcluding": "140.14.0"
            },
            {
              "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "47206424-A249-46CE-9776-F45A49344204",
              "versionEndExcluding": "153.1.0",
              "versionStartIncluding": "141.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security@mozilla.org"
}