CVE-2025-8871 MEDIUM

CVE-2025-8871: Everest Forms (Pro) <= 1.9.7 - Unauthenticated PHP Object Injection via PHAR Deserialization in Form Signature

Vendor Wpeverest
Product Everest Forms Pro
Weakness CWE-502 · Unsafe deserialization
Published November 5, 2025
Last update April 8, 2026
View on NVD All CVEs

CVSS base score

5.6/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

The Everest Forms (Pro) plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.9.7 via deserialization of untrusted input in the mime_content_type() function. This makes it possible for unauthenticated attackers to inject a PHP Object. This vulnerability may be exploited by unauthenticated attackers when a form is present on the site with a non-required signature form field along with an image upload field. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present. This vulnerability is only exploitable in PHP versions prior to 8.

Explanation of Vulnerability in Simple Terms

02Summary

Everest Forms Pro versions up to 1.9.7 contain a deserialization vulnerability that allows attackers to deserialize untrusted data. An attacker can exploit this by sending a specially crafted request over the network, potentially leading to information disclosure, data modification, or service disruption. No user interaction or special privileges are required.

What an attacker can do

03Attacker Capabilities

Deserialize untrusted data to read sensitive information, modify data, or disrupt the form service.

Potential impact on your site

04Site Impact

Attackers can read form data, modify submissions, or cause the form service to become unavailable without needing to log in.

Conditions required to exploit

05Prerequisites

Network access to the vulnerable Everest Forms Pro installation; no authentication required.

Key dates

06Disclosure timeline

November 5, 2025 CVE published
April 8, 2026 Record updated