Affected versions: < 1.21.1
Full advisory: our disclosure post
CVE-2026-76570CriticalCVSS 10.0Published 30 September 2026
JCTables (com_jctables) below 1.21.1 - Unauthenticated SQL Injection (database read and write, leading to RCE)
JCTables by JoomCode before 1.21.1 exposes a front-end CRUD controller (index.php?option=com_jctables&task=...) that performs no Joomla token validation and no authentication check on any task. Table names, column names and values are taken straight from the request and concatenated into SQL, and the escaping helper treats any quote-wrapped value as already escaped. An anonymous visitor can read any table in the Joomla database (including the users table) and write to any row, which is enough to take over an administrator account and from there install code on the site. No login or user interaction is needed (CVSS 4.0 10.0 Critical). Update JCTables to 1.21.1 or later, which adds token checks to the write tasks, always quotes values, and limits reads to administrator-configured tables. If you cannot update straight away, disable or uninstall the component until you can, and review administrator accounts for changes.
Affected versions: < 1.21.1
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.
How CVE-2026-76570 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 CNACVSS: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:YHow 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
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 30 September 2026.