By ByteBot
CISA added CVE-2026-48907 to its Known Exploited Vulnerabilities catalog on June 16. The flaw lives in Joomla Content Editor (JCE) — the most widely installed third-party editor plugin in the Joomla ecosystem — and carries a maximum CVSS score of 10.0. No authentication required. Public exploit code is live. Automated scanners are already sweeping the internet for vulnerable sites. Federal agencies have until July 7 to patch; if you manage a Joomla site, do not wait that long.
What Is JCE and Why Does It Matter Here
JCE is a WYSIWYG rich-text editor that replaces Joomla’s built-in editor with a more capable alternative. It is installed on an estimated 83% of Joomla sites — which collectively represent around 600,000 to 900,000 websites globally. That is a large target surface for automated exploitation, and the attackers are already scanning it.
How the Attack Works
CVE-2026-48907 is not a single bug. It is three design failures stacked on top of each other. The JCE profile import handler (task=profiles.import) has no authentication check: any caller who can obtain a CSRF token — trivially available from any public page — can invoke it. The imported profile is staged to Joomla’s /tmp/ directory without content validation, and Joomla’s default configuration allows PHP execution from that directory.
The attack chain runs in under a minute. An attacker uploads a malicious editor profile that re-enables .php file uploads. Then they use that profile to drop a web shell — a persistent PHP backdoor — onto the server. From there, they have full remote code execution and can read files, exfiltrate credentials, install crypto miners, or use the server as a pivot for further attacks.
Joomla’s security team was direct: “The vulnerability is being actively exploited, working exploit code is public, and the attacks are automated, so a site with no public registration is not safe.“
Patch Now: Update JCE to 2.9.99.6
The fix is straightforward. Patch to JCE version 2.9.99.6 — not just 2.9.99.5. The initial patch dropped June 3; 2.9.99.6 followed on June 8 with additional hardening that the earlier release did not include. Go to your Joomla admin panel: Extensions > Manage > Update tab. Search for JCE, run the update. The process takes about 90 seconds. Both the free Core version and JCE Pro are affected and both have updated releases available.
Check Whether You Were Already Hit
Patching stops new attacks. It does not remove web shells already on your server. Before assuming you are clean, check these indicators of compromise:
- JCE editor profiles named
Jfollowed by six digits (J938560, J991471, J940401). This naming pattern is specific to the exploit kit currently in active use. - Unexpected PHP files in
/tmp/,/media/, or/images/. - Hidden files with double extensions like
.xml.phpor.txt.php.
You can also grep your server access logs for exploitation attempts:
grep -i "option=com_jce&task=profiles.import" /var/log/apache2/access.logUnauthenticated POST hits in that log before your patch date mean you should treat the server as compromised: run a full malware scan, rotate all administrator and database credentials, and notify your hosting provider. mySites.guru has a dedicated scanner that can find rogue JCE profiles and web shells across multiple Joomla installs from one dashboard.
If You Cannot Patch Immediately
If updating JCE is blocked by compatibility testing or change-management processes, two interim steps reduce exposure. First, disable or uninstall JCE entirely via Extensions Manager until the update is cleared. Second, add a WAF rule blocking POST requests matching option=com_jce&task=profiles.import. Neither is a substitute for patching, but they interrupt the automated attack chain while you work through your process.
The Deadline Is July 7 — for Federal Agencies
Under CISA Binding Operational Directive 22-01, federal civilian agencies must remediate CVE-2026-48907 by July 7, 2026. That is the compliance floor for the highest-stakes environments. The automated scanners targeting this vulnerability operate on no such schedule. The patch is available, the risk is confirmed, and the update takes less than two minutes to apply.
