CVE-2026-4666
wpForo Forum <= 2.4.16 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Forum Post Modification via 'guestposting' Parameter
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.
INFO
Published Date :
April 17, 2026, 4:16 a.m.
Last Modified :
April 17, 2026, 4:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-4666
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the wpForo Forum plugin to the latest version.
- Verify plugin updates address the extract() function vulnerability.
- Restrict user permissions to the minimum required level.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-4666.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4666 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-4666
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-4666 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-4666 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Apr. 17, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-862 Added Reference https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Actions.php#L773 Added Reference https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Posts.php#L283 Added Reference https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/classes/Posts.php#L285 Added Reference https://plugins.trac.wordpress.org/browser/wpforo/tags/2.4.16/includes/functions.php#L532 Added Reference https://plugins.trac.wordpress.org/changeset?old_path=%2Fwpforo/tags/2.4.16&new_path=%2Fwpforo/tags/2.4.17 Added Reference https://ti.wordfence.io/vendors/patch/1885/download Added Reference https://wordpress.org/plugins/wpforo/ Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/049ffab1-677d-4112-9f1d-092ee01299f1?source=cve