Security Alert Summary
The Fluent Forms Pro Add On Pack plugin for WordPress contains a PHP Object Injection vulnerability that affects all versions up to and including 6.2.6. Authenticated users with Subscriber-level access and above can exploit deserialization of untrusted input to inject PHP objects. With a suitable POP chain and when user update integration is enabled with a mapped user meta field, an attacker can change user passwords and potentially take over administrator accounts.
CVE Details
- CVE ID:
CVE-2026-15962 - Affected component: Fluent Forms Pro Add On Pack plugin for WordPress
- Affected versions: All versions up to and including 6.2.6
- Published: July 26, 2026 at 02:16:28 AM UTC
- Last modified: July 26, 2026 at 02:16:28 AM UTC
- CVSS v3.1: Base Score 8.8, Severity HIGH, Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Authentication / privileges / user interaction: Requires an authenticated user (Subscriber-level access or higher). Privileges required: Low. User interaction: None.
- Primary impact: Confidentiality: High; Integrity: High; Availability: High
- Weakness (CWE): CWE-502 (Deserialization of Untrusted Data)
Technical Details
This vulnerability is a PHP Object Injection resulting from the deserialization of untrusted input in the plugin. An authenticated attacker with Subscriber-level access or higher can supply serialized data that, when deserialized by the plugin, allows injection of a PHP object. The presence of a suitable POP chain (property oriented programming chain) within the application logic enables the attacker to escalate the effects of injected objects.
The CVE description notes that exploitation can allow changing user passwords and potentially taking over administrator accounts, but this exploitation is conditional: it requires that the plugin’s user update integration feature is enabled and that a user meta field is mapped. No specific functions or REST endpoints are named in the provided data; the root cause is unsafe deserialization of attacker-controlled input.
How This Could Impact Your Website
In a typical site environment, the site owner manages administrators, internal staff manage content, and external contractors or contributors may have Subscriber or Contributor accounts. If an attacker with a Subscriber-level account successfully exploits this vulnerability, they could alter user-related data where the plugin integrates with user updates. A realistic scenario includes:
- An external contractor with Subscriber access submits specially crafted input that the plugin deserializes.
- The attacker leverages a POP chain to modify user meta and reset passwords for higher-privilege users.
- Administrators may lose access to their accounts if passwords are changed, and internal user emails or account data could be exposed or modified.
Practical consequences include exposure of internal user email addresses and an increased risk of targeted phishing or social engineering against staff and contractors. If youâre unsure whether your site is affected or how to assess your current user roles and plugins, it may be worth having a professional review.
Recommended Actions
- Update the affected plugin as soon as a patched version is available.
- Disable or review user update integrations and remove any unnecessary user meta mappings until the plugin is patched.
- Review and reduce unnecessary user roles, especially Contributor and Subscriber accounts that are not required.
- Enforce strong passwords and two-factor authentication for editors and administrators.
- Remove unused or unmaintained plugins from your site.
- Monitor site activity and user account changes for unusual behavior such as unexpected password resets or profile edits.
If youâd like help reviewing your plugins, user roles, or overall WordPress security posture, our team at Freshy is happy to help.
