CVE-2026-28555: wpForo Forum 2.4.14 Missing Authorization via Topic Close AJAX Handler

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-28 · updated 2026-06-17
Weakness: CWE-862

Description

wpForo Forum 2.4.14 contains a missing authorization vulnerability that allows authenticated subscribers to close or reopen any forum topic via the wpforo_close_ajax handler. Attackers submit a valid nonce with an arbitrary topic ID to bypass the moderator permission requirement and disrupt forum discussions.

Affected products

tomdever wpForo Forum: from 2.4.0 before 2.4.16 — fixed in 2.4.16

How to fix

Upgrade to a fixed version: tomdever wpForo Forum 2.4.16. Check the vendor advisory for mitigations.

References

https://wordpress.org/plugins/wpforo/
https://wordpress.org/plugins/wpforo/#developers
https://www.vulncheck.com/advisories/wpforo-forum-missing-authorization-via-topic-close-ajax-handler

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