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CriticalPHP2Shell is fixed, but a researcher now claims six more unpatched PHP flaws. Nothing to do today, but PHP is not out of the woodsWhat to prepare
CVE-2025-54300HighCVSS 8.5CVE published 25 August 2025Added to mySites.guru 25 August 2025

Quantum Manager (com_quantummanager) below 3.2.1 - Stored XSS (SVG upload and filename)

Quantum Manager file manager. CVE-2025-54300 (unsanitised SVG upload) and CVE-2025-54301 (unescaped file names) lead to stored XSS. Affects 1.0.0-3.2.0, fixed in 3.2.1.

Is my site affected?

Affected
Quantum Manager before 3.2.1
Fixed in
3.2.1
What to do
Update Quantum Manager to 3.2.1 or later.
Check whether your sites are affected

How CVE-2025-54300 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.

8.5 High

CVSS 4.0, scored by Joomla CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/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:N Integrity
None. Nothing can be altered
VA:N Availability
None. The site stays up

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. 25 August 2025CVE-2025-54300 record published by its CNA
  2. 25 August 2025mySites.guru check added for Quantum Manager (before 3.2.1)

Rule details

Other vulnerabilities in Quantum Manager

Updating for CVE-2025-54300 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.

Quantum Manager

Latest safe version: 3.2.1

References

CVE-2025-54300 questions

Which versions are affected by CVE-2025-54300?
CVE-2025-54300 affects Quantum Manager before 3.2.1. The fix is in 3.2.1.
How do I fix CVE-2025-54300?
Update Quantum Manager to 3.2.1 or later. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2025-54300?
Joomla CNA scores it 8.5 (High) 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?

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 25 October 2026.