MetForm <= 4.3.0 — Unauthenticated Arbitrary HTML Injection in Notification Emails
CVE-2026-86833Published · Updated Action summary
Affected: ≤4.3.0Update to 4.3.1 or newer
All remediation steps- Severity
- Medium4.7
- CVSS
- 4.7CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:RUser interaction- Required
S:CScope- Changed
C:NConfidentiality- None
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-20 Improper Input Validation
- Required access
- No account needed
- Exploit prediction (EPSS)
- 0.2% chance in 30 days5th percentile
- CISA KEV
- Not listed
On this page8
Am I affected?
- Affected≤ 4.3.0
- Patched in4.3.1
Update to 4.3.1 or newer.
You are affected if you run ≤ 4.3.0. Version 4.3.1 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under MetForm – Contact Form, Survey, Quiz, Conditional Forms, Form Templates & Custom Form Builder for Elementor.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 4.3.1, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch MetForm – Contact Form, Survey, Quiz, Conditional Forms, Form Templates & Custom Form Builder for Elementor to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to vuxvinh.
The MetForm plugin for WordPress is vulnerable to HTML Injection in all versions up to, and including, 4.3.0. This is due to insufficient output escaping on user-submitted field values before they are substituted into the HTML email body via the Metform_Shortcode::get_process_shortcode() function. This makes it possible for unauthenticated attackers to inject arbitrary HTML markup into administrator and submitter notification emails sent by the site.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in MetForm – Contact Form, Survey, Quiz, Conditional Forms, Form Templates & Custom Form Builder for Elementor
All 34| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium4.3 | Missing Authorization ≤4.3.3Update to 4.3.4 | CVE-2026-120847 | |
| Medium5.3 | Missing Authorization ≤4.3.2Update to 4.3.3 | CVE-2026-114180 | |
| Medium6.4 | Authenticated (Contributor+) Stored Cross-Site Scripting ≤4.3.0Update to 4.3.1 | CVE-2026-103339 | |
| Medium5.3 | Unauthenticated Information Exposure ≤4.3.0Update to 4.3.1 | CVE-2026-86832 | |
| Medium5.3 | 4.3.0 - Unauthenticated Information Exposure 2.2.1 – 4.3.0Update to 4.3.1 | CVE-2026-86834 |
- Medium4.3Missing Authorization
≤4.3.3Update to 4.3.4
- Medium5.3Missing Authorization
≤4.3.2Update to 4.3.3
- Medium6.4Authenticated (Contributor+) Stored Cross-Site Scripting
≤4.3.0Update to 4.3.1
- Medium5.3Unauthenticated Information Exposure
≤4.3.0Update to 4.3.1
- Medium5.34.3.0 - Unauthenticated Information Exposure
2.2.1 – 4.3.0Update to 4.3.1
Timeline
CVE published
Severity medium, CVSS 4.7
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- EPSS
- Exploit Prediction Scoring System by FIRST.org.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.