CVE-2026-28560: wpForo Forum 2.4.14 Stored XSS via Unsafe JSON Encoding in Inline Script

Severity: medium (CVSS 4.8 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-79

Description

wpForo Forum 2.4.14 contains a stored cross-site scripting vulnerability that allows script injection via forum URL data output into an inline script block using json_encode without the JSON_HEX_TAG flag. Attackers set a forum slug containing a closing script tag or unescaped single quote to break out of the JavaScript string context and execute arbitrary script in all visitors' browsers.

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

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