CVE-2026-34424

critical

Description

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.

References

Advisories
More

https://smartslider.helpscoutdocs.com/article/2144-wordpress-security-advisory-smart-slider-3-pro-3-5-1-35-compromise

https://smartslider.helpscoutdocs.com/article/2143-joomla-security-advisory-smart-slider-3-pro-3-5-1-35-compromise

https://patchstack.com/database/wordpress/plugin/nextend-smart-slider3-pro/vulnerability/wordpress-smart-slider-3-plugin-3-5-1-35-backdoor-vulnerability

https://patchstack.com/articles/critical-supply-chain-compromise-in-smart-slider-3-pro-full-malware-analysis/

https://mysites.guru/blog/smart-slider-3-pro-supply-chain-compromise/

Details

Source: Mitre, NVD

Published: 2026-04-09

Updated: 2026-04-09

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.00152