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CVE-2026-84048MediumCVSS 6.3CVE published 15 September 2026Added to mySites.guru 15 September 2026

JoomGallery (com_joomgallery) 4.0.0 to 4.4.1 - Unauthenticated Arbitrary File Upload via the TUS Endpoint

JoomGallery 4.0.0 to 4.4.1 ship a TUS resumable-upload endpoint with improper access control (CWE-284), letting an unauthenticated visitor upload files to the server. The Joomla CNA scored it CVSS 4.0 6.3 Medium. The vendor rates the practical risk as high and says it can be exploited on any JoomGallery 4.x installation, whatever the gallery configuration. The attacker controls neither the file name nor the file extension, so a default install does not hand over remote code execution, but on a poorly configured server the uploaded file may still be executable and the server compromised. Found by Yugorin of Samar Group, reported to the vendor on 12 September 2026. Uploaded files are dropped in the configured Joomla temp directory as a 32-character hexadecimal name alongside a matching .info file, for example aabbccddeeff00112233445566778899 and aabbccddeeff00112233445566778899.info. Fix: update to JoomGallery 4.4.2 (18 September 2026) or later. 4.4.2 adds a CSRF token check, a user identity check and per-category ACL checks to the TUS server, and enforces the configured upload size limit. After updating, inspect the Joomla temp directory, delete any files matching that pattern, and check the site for other signs of tampering. Temporary mitigation if you cannot update immediately: block access to the TUS upload endpoint of the component at the web server or WAF. The CVE record disagrees with itself on the affected range: the title says "JoomGallery < 4.4.1" while the structured version list says 4.0.0-4.4.1. The version list is the correct half, and the vendor confirms 4.4.1 is affected and 4.4.2 is the fix. JoomGallery 3.x does not include the TUS server and is unaffected.

Is my site affected?

Affected
JoomGallery from 4.0.0 up to but not including 4.4.2
Fixed in
4.4.2
What to do
Update JoomGallery to 4.4.2 or later.
Check whether your sites are affected

How CVE-2026-84048 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.

6.3 Medium

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

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: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:N Confidentiality
None. Nothing can be read
VI:L Integrity
Low. Some data can be altered
VA:N Availability
None. The site stays up

What it does beyond the site

SC:N Confidentiality
None. Other systems keep their data
SI:N Integrity
None. Other systems keep their integrity
SA:N Availability
None. Other systems stay up

Timeline

  1. 15 September 2026CVE-2026-84048 record published by its CNA
  2. 15 September 2026mySites.guru check added for JoomGallery (from 4.0.0 up to but not including 4.4.2)

Rule details

Other vulnerabilities in JoomGallery

Updating for CVE-2026-84048 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.

JoomGallery

Latest safe version: 4.4.2

References

CVE-2026-84048 questions

Which versions are affected by CVE-2026-84048?
CVE-2026-84048 affects JoomGallery from 4.0.0 up to but not including 4.4.2. The fix is in 4.4.2.
How do I fix CVE-2026-84048?
Update JoomGallery to 4.4.2 or later. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2026-84048?
Joomla CNA scores it 6.3 (Medium) 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?

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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 8 October 2026.