Auth bypass in Gvectors Wpforo Forum
CVE-2026-28557
wpForo Forum 2.4.14 contains a missing capability check vulnerability that allows authenticated users to trigger bulk wpForo usergroup reassignment via the wpforo_synch_roles AJAX handler. Attackers access the usergroups admin page, accessible to any authenticated user, to obtain a nonce, then remap all wpForo usergroups to arbitrary WordPress roles.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Gvectors Wpforo Forum
- Gvectors Team Wpforo Forum — versions 2.4, 2.4.16
Weakness classification (CWE)
References
- wordpress.org/plugins/wpforo/ (Product, product)
- wordpress.org/plugins/wpforo/ (Release Notes, patch)
- www.vulncheck.com/advisories/wpforo-forum-privilege-escalation-via-role-synchro… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-28557?
- CVE-2026-28557 is a medium-severity vulnerability in Gvectors Wpforo Forum, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-02-28.
- How severe is CVE-2026-28557?
- Medium severity. CVSS v3 base score is 6.5 out of 10.