What is CVE-2026-34424?

CVE-2026-34424 is a critical-severity vulnerability in Nextendweb Smart Slider 3 Pro For Joomla, classified under CWE-506. CVSS score: 9.8/10. Published 2026-04-09.

How severe is CVE-2026-34424?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Nextendweb Smart Slider 3 Pro For Joomla

CVE-2026-34424

Smart Slider 3 Pro version 3.5.1.35 for WordPress and Joomla contains a multi-stage remote access toolkit injected through a compromised update system that allows unauthenticated attackers to execute arbitrary code and commands. Attackers can trigger pre-authentication remote shell execution via HTTP headers, establish authenticated backdoors accepting arbitrary PHP code or OS commands, create hidden administrator accounts, exfiltrate credentials and access keys, and maintain persistence through multiple injection points including must-use plugins and core file modifications.

Published 2026-04-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (60.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 60.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.010 · change: +0.004

Affected products

Nextendweb Smart Slider 3 Pro For Joomla — versions 3.5.1.35, 0, 3.5.1.36
Nextendweb Smart Slider 3 Pro For WordPress — versions 3.5.1.35, 0, 3.5.1.36

Weakness classification (CWE)

CWE-506

References

smartslider.helpscoutdocs.com/article/2144-wordpress-security-advisory-smart-sl… (vendor-advisory, patch)
smartslider.helpscoutdocs.com/article/2143-joomla-security-advisory-smart-slide… (vendor-advisory, patch)
patchstack.com/database/wordpress/plugin/nextend-smart-slider3-pro/vulnerabilit… (third-party-advisory)
patchstack.com/articles/critical-supply-chain-compromise-in-smart-slider-3-pro-… (technical-description)
mysites.guru/blog/smart-slider-3-pro-supply-chain-compromise/ (technical-description)

Frequently asked questions

What is CVE-2026-34424?: CVE-2026-34424 is a critical-severity vulnerability in Nextendweb Smart Slider 3 Pro For Joomla, classified under CWE-506. CVSS score: 9.8/10. Published 2026-04-09.
How severe is CVE-2026-34424?: Critical severity. CVSS v3 base score is 9.8 out of 10.