Auth bypass in Nextendweb Smart Slider 3

CVE-2026-4065

The Smart Slider 3 plugin for WordPress is vulnerable to unauthorized access and modification of data due to missing capability checks on multiple wp_ajax_smart-slider3 controller actions in all versions up to, and including, 3.5.1.33. The display_admin_ajax() method does not call checkForCap() (which requires unfiltered_html capability), and several controller actions only validate the nonce (validateToken()) without calling validatePermission(). This makes it possible for authenticated attackers, with Contributor-level access and above, to enumerate slider metadata and create, modify, and delete image storage records by obtaining the nextend_nonce exposed on post editor pages.

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 (22.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.5% 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-2026-4065: held from 0.004 to 0.003.

EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4065?
CVE-2026-4065 is a medium-severity vulnerability in Nextendweb Smart Slider 3, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-04-07.
How severe is CVE-2026-4065?
Medium severity. CVSS v3 base score is 5.4 out of 10.