CVE-2026-3296: 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 untrus...

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.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.88%

54.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-502

References

Timeline

Published: Apr 8, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3296?

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.

How severe is CVE-2026-3296?

CVE-2026-3296 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.88% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3296?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.