Security Alert Summary
The wpForo Forum WordPress plugin before 3.1.6 contains a PHP object injection vulnerability that arises when a user-supplied profile field value is deserialized without restricting which classes may be instantiated. Authenticated users with Subscriber-level access and above can supply crafted data that results in object injection. While the plugin itself does not include a gadget/POP chain, the presence of a usable chain in another installed component could escalate the impact to remote code execution or other serious outcomes.
CVE Details
- CVE ID:
CVE-2026-80513 - Affected component: wpForo Forum WordPress plugin
- Affected versions: Versions before 3.1.6 (less than 3.1.6)
- Published: September 24, 2026 at 6:17:01 AM UTC
- Last modified: September 24, 2026 at 2:42:02 PM UTC
- CVSS v3.1 base score: 7.5
- CVSS v3.1 severity: HIGH
- CVSS vector string: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Authentication / privileges / user interaction:
- Authentication: required (authenticated users)
- Privileges required: Low (Subscriber-level access and above is sufficient)
- User interaction: None
- Primary impact: Confidentiality: High; Integrity: High; Availability: High
- CWE / weakness: CWE-502 (Deserialization of Untrusted Data)
Technical Details
The plugin deserializes a user-supplied profile field value without restricting which PHP classes may be instantiated. This allows an authenticated user with Subscriber-level access or higher to inject a PHP object during deserialization (PHP Object Injection).
The wpForo package itself does not include a POP (property-oriented programming) chain that would immediately enable code execution; however, if a suitable POP/gadget chain exists in another installed component on the same site, the injected object could be leveraged to perform remote code execution, arbitrary file operations, or SQL injection. The issue is described as an incomplete fix of CVE-2026-49769 in the plugin’s prior handling.
No specific functions or REST endpoints are named in the available information; the root cause is the lack of class restriction during deserialization of profile field data.
How This Could Impact Your Website
Consider a small team running a community forum: the site owner manages plugins and users, an internal staff member moderates posts, and an external contributor or contractor has a Subscriber or Contributor account for posting. Because the vulnerability allows object injection from profile field data submitted by authenticated users, a malicious contributor could craft profile content that instantiates unintended classes when deserialized.
Possible practical consequences include disclosure of internal user data (for example, email addresses stored in user profiles), increased risk of targeted phishing or social engineering against staff or contributors, and, if a gadget chain is present elsewhere on the site, escalation to file access or execution-level impacts. The likelihood and extent of these impacts depend on other installed plugins and server-side components; the plugin alone does not always result in remote code execution.
professional review If youre unsure whether your site is affected or how to assess your current user roles and plugins, it may be worth having a professional review your setup.
Recommended Actions
- Update the affected plugin as soon as a patched version is available.
- Review and reduce unnecessary user roles, especially Contributor and Subscriber accounts with write access.
- Enforce strong passwords and two-factor authentication for editors and administrators.
- Remove unused or unmaintained plugins that could provide gadget chains.
- Monitor site activity and logs for unusual behavior related to profile updates, file changes, or unexpected database activity.
If youd like help reviewing your plugins, user roles, or overall WordPress security posture, our team at Freshy is happy to help.
