CVE-2026-3296
CriticalExploitedEverest Forms <= 3.4.3 - Unauthenticated PHP Object Injection via Form Entry Metadata
Published Apr 9, 2026 · Updated Jul 25, 2026 · Also known as 2693ae37-790d-4b18-a9ec-054c8c27b8bc
Key Facts
Patch immediately- CVE-2026-3296 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting everest-forms (wordpress-plugin), Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder.
- It is exploited in the wild, listed in Industry KEV feed since May 4, 2026. No public exploit code is known.
- EPSS estimates a 3.0% probability of exploitation in the next 30 days.
- Fixed versions are available, including everest-forms 3.4.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
3.0%
Higher than 87.0% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
None known
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Description
The Everest Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.4.3 via deserialization of untrusted input from form entry metadata. This is due to the html-admin-page-entries-view.php file calling PHP's native unserialize() on stored entry meta values without passing the allowed_classes parameter. This makes it possible for unauthenticated attackers to inject a serialized PHP object payload through any public Everest Forms form field. The payload survives sanitize_text_field() sanitization (serialization control characters are not stripped) and is stored in the wp_evf_entrymeta database table. When an administrator views entries or views an individual entry, the unsafe unserialize() call processes the stored data without class restrictions.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | May 4, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| everest-formswordpress-plugin | See advisory | 3.4.4 |
| Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder | See advisory | n/a |
Patched Releases
everest-forms
3.4.4
Timeline
Publicly disclosed
Apr 9, 2026
Added to Industry KEV feed
May 4, 2026
Last updated
Jul 25, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryhttps://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L186
- advisoryhttps://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L190
- advisoryhttps://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-ajax-nopriv.php#L233
- advisoryhttps://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-common.php#L168
- advisoryhttps://plugins.trac.wordpress.org/browser/userspn/tags/1.0.31/includes/class-userspn-functions-user.php#L235
FAQ
Common Questions.
The Everest Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.4.3 via deserialization of untrusted input from form entry metadata.
Affected: everest-forms (wordpress-plugin); Everest Forms – Contact Form, Payment Form, Quiz, Survey & Custom Form Builder. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since May 4, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including everest-forms 3.4.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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