CVE-2026-57831: Joomla DP Calendar SQLi Vulnerability

CVE-2026-57831 Overview

CVE-2026-57831 is an unauthenticated SQL injection vulnerability in DP Calendar, a Joomla extension developed by Digital Peak. The flaw allows remote attackers to inject arbitrary SQL statements without providing credentials. Successful exploitation enables adversaries to read sensitive data from the underlying Joomla database, including user records, session tokens, and configuration values. The vulnerability is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command. Because DP Calendar is a widely deployed event management extension, the flaw exposes public-facing Joomla sites to database compromise through crafted HTTP requests.

Critical Impact
Unauthenticated attackers can extract sensitive database contents from Joomla sites running vulnerable DP Calendar installations by sending crafted requests over the network.

Affected Products

Digital Peak DP Calendar (Joomla extension)
Joomla sites with DP Calendar installed and publicly accessible
See the Digital Peak Product Page for supported deployments

Discovery Timeline

2026-07-15 - CVE-2026-57831 published to NVD
2026-07-15 - Last updated in NVD database

Technical Details for CVE-2026-57831

Vulnerability Analysis

The vulnerability resides in DP Calendar's request handling logic, where user-supplied input reaches SQL query construction without proper sanitization or parameterization. Attackers submit crafted parameters through HTTP requests to endpoints exposed by the extension. The unsanitized input is concatenated into database queries executed by the Joomla backend. Because no authentication is required, any remote client that can reach the site can trigger the flaw. Exploitation can yield read access to arbitrary tables in the Joomla database, including the #__users table containing hashed credentials and session data.

The attack requires low complexity and no user interaction. The CVSS vector indicates network-based exploitation with high confidentiality impact, while integrity and availability impact are rated none, consistent with a data-extraction primitive rather than write or destructive capability.

Root Cause

The root cause is improper neutralization of special characters in SQL commands [CWE-89]. Input received from HTTP request parameters is passed into query builders or raw SQL strings without using bound parameters or context-aware escaping. This allows attackers to break out of the intended query context and append additional SQL clauses such as UNION SELECT statements.

Attack Vector

An attacker sends an HTTP request to a vulnerable DP Calendar endpoint on a public Joomla site. The malicious parameter contains SQL metacharacters and injected clauses. The extension processes the request, constructs a database query containing attacker-controlled SQL, and executes it. Responses may return injected data directly in page output or through error-based, boolean-based, or time-based inference techniques. Refer to the MySites Guru SQL Injection Disclosure for details on the disclosed attack surface.

Detection Methods for CVE-2026-57831

Indicators of Compromise

HTTP requests to DP Calendar endpoints containing SQL keywords such as UNION, SELECT, SLEEP(, BENCHMARK(, or encoded variants
Web server logs showing abnormally long query strings targeting option=com_dpcalendar parameters
Unexpected database queries against Joomla tables such as #__users or #__session originating from the web application user
Elevated response times on DP Calendar URLs, indicative of time-based blind SQL injection probes

Detection Strategies

Deploy web application firewall (WAF) rules that flag SQL injection payload patterns in requests to /index.php?option=com_dpcalendar and related paths
Enable Joomla and MySQL query logging to correlate suspicious HTTP requests with anomalous SQL statements
Hunt for repeated 500-series errors from DP Calendar endpoints, which often accompany error-based injection attempts

Monitoring Recommendations

Forward web server access logs and database audit logs to a centralized SIEM for correlation and long-term retention
Alert on high-volume access to DP Calendar endpoints from single source IP addresses
Baseline normal parameter values for DP Calendar requests and alert on statistical outliers containing SQL syntax

How to Mitigate CVE-2026-57831

Immediate Actions Required

Inventory all Joomla installations and identify sites using the DP Calendar extension
Update DP Calendar to the latest version released by Digital Peak that addresses CVE-2026-57831
Review web server and database logs for signs of prior exploitation, focusing on requests preceding the patch date
Rotate Joomla administrator credentials and invalidate active sessions if compromise is suspected

Patch Information

Digital Peak has published product information at the Digital Peak Product Page. Site administrators should apply the vendor-provided update through the Joomla Extensions Manager and confirm the installed version reflects the fixed release. Consult the MySites Guru SQL Injection Disclosure for additional remediation guidance.

Workarounds

Temporarily disable the DP Calendar component in the Joomla administrator panel until patching is complete
Restrict access to DP Calendar endpoints using WAF rules or .htaccess allowlists while remediation is planned
Apply WAF signatures that block common SQL injection payloads targeting the com_dpcalendar component

bash

# Example .htaccess rule to restrict access to DP Calendar endpoints
<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteCond %{QUERY_STRING} option=com_dpcalendar [NC]
  RewriteCond %{REMOTE_ADDR} !^203\.0\.113\. 
  RewriteRule ^ - [F,L]
</IfModule>