#VU125748 Embedded malicious code (backdoor) in Smart Slider 3
Published: April 9, 2026
Vulnerability identifier: #VU125748
Vulnerability risk: Critical
CVSSv4.0: 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/E:A/U:Red
CVE-ID: N/A
CWE-ID: CWE-506
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Smart Slider 3
Smart Slider 3
Software vendor:
Nextend
Nextend
Description
The vulnerability allows a remote attacker to gain unauthorized access to the application.
The vulnerability exists due to presence of embedded malicious functionality in the application code (aka backdoor) that allows a remote attacker to gain unauthorized access to the application.
Note, an unauthorized party gained access to Nextend update infrastructure on April 7 and distributed a fully attacker-authored build through the official update channel. Only version 3.5.1.35 contained the backdoor code.
Remediation
Install latest version from vendor's website.