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CVE-2026-102427CriticalCVSS 10.0Published 30 September 2026

OS CCK (com_os_cck) below 8.3.16 - Unauthenticated Arbitrary File Upload (RCE)

OrdaSoft OS CCK versions 1.0.0 to 8.3.15 let anyone upload and run PHP on the site with no login. The front-end upload handler (site/uploader.php, reached through the component's normal routing as task=getContent) has no authentication or permission check. It checks the uploaded file's content with a magic-byte MIME test, but the file-extension allow-list that should restrict the saved name was commented out, so the extension is taken straight from the attacker's filename and the file is written under the site's /images folder, where PHP executes it. A file that starts with valid image bytes and has PHP appended passes the check as a .php file. CVE-2026-102427, CVSS 4.0 10.0 Critical. OrdaSoft fixed this in 8.3.16 by enforcing a jpg/jpeg/png/gif/webp extension allow-list. OrdaSoft's Joomla update manifest still advertises 8.3.14, so sites are not offered 8.3.16 automatically: download it from ordasoft.com and install it by hand. The Pro edition shares the element; its fixed version could not be confirmed. If you cannot update, disable the component, and check /images/com_os_cck*/original/ for any .php file.

Affected versions: ≥ 1.0.0 and < 8.3.16

Official record: cve.org · NVD

Every connected Joomla site is checked against this rule on each audit, and flagged if it runs an affected version.

Check whether your sites are affected

How CVE-2026-102427 is scored

The base metrics as Joomla CNA published them, and what each one means for a site running an affected version. Threat and environmental metrics are left out: they describe a moment or a particular install rather than the flaw.

10.0 Critical

CVSS 4.0, scored by Joomla CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y

How it is reached

AV:N Attack vector
Network. Reachable across the internet
AC:L Attack complexity
Low. Nothing to work around, it just works
AT:N Attack requirements
None. Works against any affected install
PR:N Privileges required
None. No account needed
UI:N User interaction
None. Nobody has to be tricked into anything

What it does to the site

VC:H Confidentiality
High. Everything the site holds can be read
VI:H Integrity
High. Data and files can be altered at will
VA:H Availability
High. The site can be taken down

What it does beyond the site

SC:H Confidentiality
High. Data on other systems can be read
SI:H Integrity
High. Other systems can be altered
SA:H Availability
High. Other systems can be taken down

Affected extensions and versions

Our disclosure post

OS CCK 8.3.16 for Joomla Fixes a No-Login PHP Upload and an SQL Injection, but the Updater Still Offers 8.3.14

OS CCK 8.3.16 for Joomla Fixes a No-Login PHP Upload and an SQL Injection, but the Updater Still Offers 8.3.14

OS CCK for Joomla before 8.3.16 let anyone upload and run PHP (CVE-2026-102427, CVSS 10.0) and had a no-login SQL injection. The updater won't offer the fix.

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Rules current as of 30 September 2026.