Joomla\!Application · Joomla
CVE-2026-48904
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn improper access check allows privelege escalation through the com_users group editing webservice endpoint.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceAn authorization flaw in the com_users component's group editing webservice endpoint allows authenticated users to escalate privileges by improperly accessing or modifying user group permissions they should not have access to.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Joomla\!Application
>= 4.0.0, < 5.4.6>= 6.0.0, < 6.1.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Joomla versionNavigate to System > Information > Joomla Information in the admin panel, or inspect the /libraries/cms/version.php file to find the $RELEASE and $DEV_LEVEL values. Alternatively, check the VERSION file in the Joomla root directory.Affected if The installed version is >= 4.0.0 and < 5.4.6, OR >= 6.0.0 and < 6.1.1
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Verify com_users component is accessibleAccess the Joomla admin panel and navigate to Users > Manage to confirm the com_users component is installed and enabled. Also check if the /api/index.php/v1/users endpoint is accessible.Affected if The component is installed and the REST API is functional for authenticated users
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Confirm webservice endpoint exists and is reachableSend an authenticated GET request to the REST API endpoint for user group operations (typically /api/index.php/v1/users/groups or similar user group assignment endpoints) using a non-administrator account.Affected if The endpoint responds and accepts requests from authenticated users with standard user privileges
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Inspect user group modification permissionsIn the admin panel, go to Users > Access Levels and examine which user groups have permission to Edit User in Users > Options > Component Permissions. Check if regular (non-superuser) users can modify group assignments.Affected if Non-administrator user accounts can modify their own or other users' group assignments through the API without receiving a 403 Forbidden response
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Test for privilege escalation via group assignmentUsing a regular authenticated user account (not admin), attempt to modify the group assignments through the com_users webservice API to add the Super User group or an elevated privilege group to the account.Affected if The API request succeeds and the user's assigned groups are modified beyond their original permissions, indicating missing authorization validation
A user is affected if their Joomla installation version falls within the affected ranges (4.0.0 to 5.4.5 or 6.0.0 to 6.1.0) AND non-administrator accounts can modify user group assignments through the webservice API without proper authorization checks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.4.66.1.1
Implement proper role-based access control (RBAC) checks on the com_users group editing endpoint to verify user permissions before allowing group modifications; enforce least-privilege principles.
Joomla! 5.4.6 or later for 5.x branch; Joomla! 6.1.1 or later for 6.x branch
- 1. Backup your Joomla! database and files before making any changes.
- 2. Identify your current Joomla! version by accessing the Administrator dashboard or checking configuration.php.
- 3. For Joomla! 4.x (versions 4.0.0 through 5.4.5): Download Joomla! 5.4.6 from the official Joomla! downloads page.
- 4. For Joomla! 6.x (versions 6.0.0 through 6.1.0): Download Joomla! 6.1.1 from the official Joomla! downloads page.
- 5. Extract the upgrade package to your web server, overwriting existing files while preserving your configuration.php and any custom modifications.
- 6. Run the database migration script by accessing your site URL followed by /administrator/index.php?option=com_installer&task=update.finalise
- 7. Clear all Joomla! caches through System > Clear Cache.
- 8. Verify the upgrade was successful by checking the Joomla! version in the Administrator dashboard.
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Joomla\!
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-48904 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-48904 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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