CVE-2026-4666
wpForo Forum <= 2.4.16 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Forum Post Modification via 'guestposting' Parameter
- State
- Published
- Severity
- 6.5 Medium
- Published
- Apr 17, 2026
- Updated
- Apr 20, 2026
- Reserved
- Mar 23, 2026
Description
The wpForo Forum plugin for WordPress is vulnerable to unauthorized modification of data due to the use of `extract($args, EXTR_OVERWRITE)` on user-controlled input in the `edit()` method of `classes/Posts.php` in all versions up to, and including, 2.4.16. The `post_edit` action handler in `Actions.php` passes `$_REQUEST['post']` directly to `Posts::edit()`, which calls `extract($args, EXTR_OVERWRITE)`. An attacker can inject `post[guestposting]=1` to overwrite the local `$guestposting` variable, causing the entire permission check block to be skipped. The nonce check uses a hardcoded `wpforo_verify_form` action shared across all 8 forum templates, so any user who can view any forum page obtains a valid nonce. This makes it possible for authenticated attackers, with Subscriber-level access and above, to edit the title, body, name, and email fields of any forum post, including posts in private forums, admin posts, and moderator posts. Content passes through `wpforo_kses()` which strips JavaScript but allows rich HTML.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | Wordfence |
Weaknesses
- CWE-862 Missing Authorization
Affected Products
| Product | Versions |
|---|---|
wpForo Forumtomdever |
|
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/049ffab1-677d-4112-9f1d-092ee01299f1?source=cve
- https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Posts.php#L283
- https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Posts.php#L285
- https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Actions.php#L773
- https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/includes/functions.php#L532
- https://wordpress.org/plugins/wpforo/
- https://ti.wordfence.io/vendors/patch/1885/download
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fwpforo/tags/2.4.16&new_path=%2Fwpforo/tags/2.4.17
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