Affected versions: exactly 3.5.1.35
Full advisory: our disclosure post
CVE-2026-34424CriticalPublished 8 April 2026
CRITICAL: Smart Slider 3 Pro 3.5.1.35 is a COMPROMISED build - treat this site as HACKED
The Smart Slider 3 Pro 3.5.1.35 release for Joomla is a malicious build pushed through a breach of the Nextend update infrastructure. Any Joomla site that installed this version must be treated as fully compromised: the payload creates hidden Super User accounts (typically usernames beginning wpsvc_), drops backdoor files at /cache/cf_check.php and /media/cf_check.php, allows remote code execution and exfiltrates credentials. Update to Smart Slider 3 Pro 3.5.1.36 immediately, manually remove any wpsvc_ Super Users, delete the cf_check.php backdoor files, reinstall Joomla core and every extension from clean sources, and rotate every credential (Joomla admins, FTP, database, hosting and email). Also within this rule: CVE-2026-34424 (NVD record for this same compromised 3.5.1.35 build).
Affected versions: exactly 3.5.1.35
Official record: cve.org · NVD
Related vulnerabilities
Every connected Joomla site is checked against this rule on each audit, and flagged if it runs an affected version.
Affected extensions and versions
Our disclosure post
Running an affected version on a site you manage?
A free audit tells you which of your Joomla and WordPress sites run an affected version, which are out of date, and which have not been backed up. No card required. If a site is already compromised, fix.mysites.guru is a single fixed fee per incident, usually resolved the same day.
Rules current as of 25 August 2026.