Smart Slider 3 Pro security vulnerabilities

mySites.guru tracks 2 vulnerabilities in smartslider3. Every connected Joomla site is checked against them on each audit, and flagged if it runs an affected version.

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CriticalCVE-2026-344242026-04-08

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

Full advisory: our disclosure post

Medium2026-03-27

Smart Slider 3 <= 3.5.1.33 - Authenticated (Subscriber+) Arbitrary File Read via actionExportAll

The Smart Slider 3 plugin for Joomla is vulnerable to Arbitrary File Read in all versions up to, and including, 3.5.1.33 via the 'actionExportAll' function. This makes it possible for authenticated attackers, with Subscriber-level access and above, to read the contents of arbitrary files on the server, which can contain sensitive information. The Joomla version shares the same vulnerable codebase as the WordPress version.

Affected versions: ≥ 1.999.999 and ≤ 3.5.1.33

Full advisory: our disclosure post

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CVE identifiers: CVE-2026-34424. Rules current as of 13 September 2026.