Vulnerability-Lookup

CVE-2026-18431 (GCVE-0-2026-18431)

Vulnerability from cvelistv5 – Published: 2026-08-26 06:08 – Updated: 2026-08-27 14:34

Title

Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write

Summary

The Avada theme for WordPress is vulnerable to Arbitrary File Write in all versions up to, and including, 7.16 when the Fusion Builder plugin is installed and active in versions up to, and including, 3.16. This is due to a chain of authorization and input validation weaknesses across the two components that makes it possible for unauthenticated attackers to write attacker-controlled files to the server. This can be used to create and execute arbitrary PHP files, resulting in remote code execution and complete site compromise. Successful exploitation requires both Avada and Fusion Builder to be installed and active, as well as certain administrator-authored content to be present.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-27 13:56 UTC

CWE

CWE-862 - Missing Authorization

Assigner

Wordfence mitre root

References

2 references

URL	Tags
https://www.wordfence.com/threat-intel/vulnerabil…
https://avada.com/documentation/avada-changelog/

Impacted products

2 products

Vendor	Product	Version	CPE status
themefusion	Avada (Fusion) Builder	Affected: 0 , ≤ 3.16 (semver)	guessed
ThemeFusion	Avada \| Website Builder For WordPress & WooCommerce	Affected: 0 , ≤ 7.16 (semver)	guessed

Credits

Alex Thomas Wordfence Argus

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-18431

Vulnerability from fkie_nvd - Published: 2026-08-26 07:16 - Updated: 2026-08-27 17:17

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	security@wordfence.com	https://avada.com/documentation/avada-changelog/
	security@wordfence.com	https://www.wordfence.com/threat-intel/vulnerabilities/id/5bef5bd3-8ec9-4a5b-bcdd-98952c7ef390?source=cve

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Avada (Fusion) Builder",
          "vendor": "themefusion",
          "versions": [
            {
              "lessThanOrEqual": "3.16",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "Avada | Website Builder For WordPress \u0026 WooCommerce",
          "vendor": "ThemeFusion",
          "versions": [
            {
              "lessThanOrEqual": "7.16",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@wordfence.com"
    }
  ],
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    {
      "lang": "en",
      "value": "The Avada theme for WordPress is vulnerable to Arbitrary File Write in all versions up to, and including, 7.16 when the Fusion Builder plugin is installed and active in versions up to, and including, 3.16. This is due to a chain of authorization and input validation weaknesses across the two components that makes it possible for unauthenticated attackers to write attacker-controlled files to the server. This can be used to create and execute arbitrary PHP files, resulting in remote code execution and complete site compromise. Successful exploitation requires both Avada and Fusion Builder to be installed and active, as well as certain administrator-authored content to be present."
    }
  ],
  "id": "CVE-2026-18431",
  "lastModified": "2026-08-27T17:17:29.533",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
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          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "security@wordfence.com",
        "type": "Secondary"
      }
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          "options": [
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      "source": "security@wordfence.com",
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GHSA-HM9X-G2WH-6XW7

Vulnerability from github – Published: 2026-08-26 18:31 – Updated: 2026-08-26 18:31

Details

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-18431"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-26T07:16:45Z",
    "severity": "CRITICAL"
  },
  "details": "The Avada theme for WordPress is vulnerable to Arbitrary File Write in all versions up to, and including, 7.16 when the Fusion Builder plugin is installed and active in versions up to, and including, 3.16. This is due to a chain of authorization and input validation weaknesses across the two components that makes it possible for unauthenticated attackers to write attacker-controlled files to the server. This can be used to create and execute arbitrary PHP files, resulting in remote code execution and complete site compromise. Successful exploitation requires both Avada and Fusion Builder to be installed and active, as well as certain administrator-authored content to be present.",
  "id": "GHSA-hm9x-g2wh-6xw7",
  "modified": "2026-08-26T18:31:54Z",
  "published": "2026-08-26T18:31:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18431"
    },
    {
      "type": "WEB",
      "url": "https://avada.com/documentation/avada-changelog"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5bef5bd3-8ec9-4a5b-bcdd-98952c7ef390?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-18431 (GCVE-0-2026-18431)

FKIE_CVE-2026-18431

GHSA-HM9X-G2WH-6XW7

Tags

Sightings

Nomenclature