CVE-2026-18409

Status: DeferredHigh (7.2)—

The WPForms Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Single Line Text and Paragraph Text Field Values in all versions up to, and including, 2.0.0.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit relies on the plugin's own wp_kses_allowed_html filter widening the 'post' allowlist to permit iframe elements with a data-src attribute, which is not on WordPress's URI-attribute sanitization list, allowing a javascript: URI stored in data-src to survive kses processing and subsequently be promoted to a live src attribute by the bundled admin script view-entry.min.js.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Base score: 7.2

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.34%
Percentile among all scored CVEs: 25
Score date: 10/5/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access90 %
Primary impactT1059.007 JavaScriptexecution85 %

XSS almacenado en plugin WordPress accesible sin autenticación (AV:N, PR:N, UI:N). El atacante inyecta JavaScript que se ejecuta en el navegador del usuario al acceder a la página.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Vulnerability Scanning Restrict Web-Based Content Privileged Account Management Network Segmentation Limit Access to Resource Over Network Filter Network Traffic

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Wpforms — Wpforms PRO^AI

CWEs

CWE-79

References

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-18409",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-18409",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-21T15:24:10.311364Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security@wordfence.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 7.2,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.7,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security@wordfence.com",
      "affectedData": [
        {
          "vendor": "WPForms",
          "product": "WPForms Pro",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "2.0.0.2"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-08-21T04:18:01.380",
  "references": [
    {
      "url": "https://wpforms.com/docs/how-to-view-recent-changes-to-the-wpforms-plugin-changelog/#Changelog",
      "source": "security@wordfence.com"
    },
    {
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/f26cbc41-8ed9-4dc6-a8bc-9986ecab5e6e?source=cve",
      "source": "security@wordfence.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security@wordfence.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The WPForms Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Single Line Text and Paragraph Text Field Values in all versions up to, and including, 2.0.0.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit relies on the plugin's own wp_kses_allowed_html filter widening the 'post' allowlist to permit iframe elements with a data-src attribute, which is not on WordPress's URI-attribute sanitization list, allowing a javascript: URI stored in data-src to survive kses processing and subsequently be promoted to a live src attribute by the bundled admin script view-entry.min.js."
    }
  ],
  "lastModified": "2026-08-24T16:41:13.950",
  "sourceIdentifier": "security@wordfence.com"
}