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CVE-2026-88856CriticalCVSS 9.4CVE published 20 September 2026Added to mySites.guru 20 September 2026

OS Gallery (com_osgallery) below 6.2.7 - Authenticated, Privileged Remote Code Execution and SQL Injection (3 CVEs)

OrdaSoft's OS Gallery component before 6.2.7 has three flaws exploitable by an authenticated user holding the core.manage permission on the gallery component (not administrator-wide trust). CVE-2026-88857 (CVSS 9.4): saveWatermark() writes an uploaded file to a web-accessible path using the client-supplied filename with no extension or content check, so a .php file disguised with an image Content-Type can be uploaded and executed directly. CVE-2026-88856 (CVSS 9.4): updateOSGallery(), reached via task=update_osgallery, passes a JSON request's method field to a live PHP function call using the package field as its argument, with no allow-list, reaching functions such as system, exec, shell_exec and passthru directly. CVE-2026-88855 (CVSS 8.6): saveGallery() concatenates category_names[], catOrderIds and image-ordering values into SQL with no quoting or integer cast, giving full read/write database access including UNION extraction of #__users password hashes. Update to 6.2.7 or later.

Is my site affected?

Affected
OS Gallery before 6.2.7
Fixed in
6.2.7
What to do
Update OS Gallery to 6.2.7 or later.
Check whether your sites are affected

How CVE-2026-88856 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.

9.4 Critical

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

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:H Privileges required
High. Needs an account with elevated rights
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

  1. 20 September 2026CVE-2026-88856 record published by its CNA
  2. 20 September 2026mySites.guru check added for OS Gallery (before 6.2.7)

Rule details

Other vulnerabilities in OS Gallery

Updating for CVE-2026-88856 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.

OS Gallery

Latest safe version: 6.2.7

References

CVE-2026-88856 questions

Which versions are affected by CVE-2026-88856?
CVE-2026-88856 affects OS Gallery before 6.2.7. The fix is in 6.2.7.
How do I fix CVE-2026-88856?
Update OS Gallery to 6.2.7 or later. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2026-88856?
Joomla CNA scores it 9.4 (Critical) under CVSS 4.0. In plain terms: reachable across the internet, needs an account with elevated rights 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 10 October 2026.