Auth bypass in Gvectors Wpforo Forum

CVE-2026-28556

wpForo Forum 2.4.14 contains a missing authorization vulnerability that allows authenticated subscribers to move, merge, or split any forum topic via the topic_move, topic_merge, and topic_split form action handlers. Attackers with a valid form nonce can reorganize arbitrary forum content without moderator permissions, including relocating topics to private forums.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (21.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 21.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-28556: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-28556?
CVE-2026-28556 is a medium-severity vulnerability in Gvectors Wpforo Forum, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-02-28.
How severe is CVE-2026-28556?
Medium severity. CVSS v3 base score is 5.4 out of 10.