Custom Tables
Affected versions: ≥ 1.0 and < 3.7.8
Full advisory: our disclosure post
CVE-2026-105606CriticalCVSS 9.5CVE published 2 November 2026Added to mySites.guru 2 November 2026
Custom Tables (com_customtables) below 3.7.8 - Unauthenticated Arbitrary File Upload
Custom Tables versions 1.0 to 3.7.7 let an unauthenticated visitor upload a file with an attacker-chosen extension through any public Custom Tables submission form that has a file field. The file is a polyglot that passes the MIME check, it is written to a web-accessible tmp directory, and its stored path is returned in the response. By default it is served as static content, so attackers can host phishing or malware pages on your domain. Update Custom Tables to 3.7.8 or later, which also fixes an authenticated arbitrary file deletion through the file field. Until you can update, unpublish or restrict any menu item or module that shows a public Custom Tables add or edit form, and check the site tmp folder for files you did not put there.
Is my site affected?
- Affected
- Custom Tables from 1.0 up to but not including 3.7.8
- Fixed in
- 3.7.8
- What to do
- Update Custom Tables to 3.7.8 or later.
How CVE-2026-105606 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.
9.5 Critical
CVSS 4.0, scored by Joomla CNACVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HHow 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:P Attack requirements
- Present. Needs a particular deployment or race to line up
- 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
Timeline
- 2 November 2026CVE-2026-105606 record published by its CNA
- 2 November 2026mySites.guru check added for Custom Tables (from 1.0 up to but not including 3.7.8)
- 2 November 2026We published: Custom Tables for Joomla: Unauthenticated File Upload Fixed in 3.7.8
Rule details
Our disclosure post
Other vulnerabilities in Custom Tables
Updating for CVE-2026-105606 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.
Custom Tables
Latest safe version: 3.7.8
References
- CVE-2026-105606 on cve.org (the official CVE record)
- CVE-2026-105606 in the NIST National Vulnerability Database
- Custom Tables for Joomla: Unauthenticated File Upload Fixed in 3.7.8
CVE-2026-105606 questions
Which versions are affected by CVE-2026-105606?
CVE-2026-105606 affects Custom Tables from 1.0 up to but not including 3.7.8. The fix is in 3.7.8.
How do I fix CVE-2026-105606?
Update Custom Tables to 3.7.8 or later. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2026-105606?
Joomla CNA scores it 9.5 (Critical) under CVSS 4.0. In plain terms: reachable across the internet, no account needed and nobody has to be tricked into anything.
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.
This check is part of the mySites.guru Joomla vulnerability scanner, which reads every installed extension's version on each audit. Browse the rest of the Joomla vulnerability database.
Rules current as of 3 November 2026.