FKIE_CVE-2026-8981

Vulnerability from fkie_nvd - Published: 2026-06-09 06:16 - Updated: 2026-07-23 08:10
Severity
3.5 (Low) - CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
Summary
The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.
References
contact@wpscan.comhttps://wpscan.com/vulnerability/9815b0e6-e411-4a5c-9c63-30bad21da698/
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Custom Block Builder",
          "vendor": "Unknown",
          "versions": [
            {
              "lessThan": "4.3.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "contact@wpscan.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Custom Block Builder  WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block."
    },
    {
      "lang": "es",
      "value": "El plugin de WordPress Custom Block Builder anterior a la versi\u00f3n 4.3.0 no verifica de forma consistente la capacidad unfiltered_html en todas las rutas que escriben en sus campos de c\u00f3digo de plantilla de bloque, permitiendo a los administradores en instalaciones multisitio (o instalaciones de sitio \u00fanico con DISALLOW_UNFILTERED_HTML definido) inyectar JavaScript arbitrario que se ejecuta para cualquier visitante de las p\u00e1ginas que incrustan el bloque afectado."
    }
  ],
  "id": "CVE-2026-8981",
  "lastModified": "2026-07-23T08:10:00.137",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.5,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 0.9,
        "impactScore": 2.5,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-8981",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-09T10:32:46.274624Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-09T06:16:54.067",
  "references": [
    {
      "source": "contact@wpscan.com",
      "url": "https://wpscan.com/vulnerability/9815b0e6-e411-4a5c-9c63-30bad21da698/"
    }
  ],
  "sourceIdentifier": "contact@wpscan.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}



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Sightings

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Nomenclature

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  • 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.



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