CVE-2026-9528: Electronic Judging System SQLi Flaw

CVE-2026-9528 Overview

CVE-2026-9528 is a SQL injection vulnerability in itsourcecode Electronic Judging System 1.0. The flaw resides in the /admin/delete_judge.php script, where the judge_id parameter is passed to a database query without proper sanitization. Remote attackers can manipulate this parameter to inject arbitrary SQL statements. The exploit has been publicly disclosed, increasing the likelihood of opportunistic abuse against exposed installations. The weakness is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Critical Impact
Unauthenticated remote attackers can inject SQL through the judge_id parameter to read, modify, or delete records in the application database.

Affected Products

itsourcecode Electronic Judging System 1.0
Component: /admin/delete_judge.php
Vulnerable parameter: judge_id

Discovery Timeline

2026-05-26 - CVE-2026-9528 published to NVD
2026-05-26 - Last updated in NVD database

Technical Details for CVE-2026-9528

Vulnerability Analysis

The vulnerability exists in the administrative judge deletion workflow of the Electronic Judging System. The delete_judge.php script accepts a judge_id value from client-supplied input and concatenates it directly into a SQL DELETE statement. Because the parameter is not validated, type-cast, or bound through a prepared statement, attackers can break out of the original query context and append arbitrary SQL clauses.

A remote attacker reaches the endpoint over the network without prior authentication. By substituting SQL syntax for the expected integer identifier, the attacker can enumerate database contents using time-based or boolean-based techniques, extract credentials from administrator tables, or pivot to UNION-based extraction of sensitive records. The Electronic Judging System is typically used to store competitor data, scoring information, and judge credentials, making the database an attractive target.

Root Cause

The root cause is improper neutralization of special elements passed to a downstream SQL interpreter [CWE-74]. The application trusts the judge_id HTTP parameter and constructs the deletion query through string concatenation rather than parameterized queries or input whitelisting. PHP applications written in this style routinely expose every administrative endpoint to similar attacks.

Attack Vector

Attackers send a crafted HTTP request to /admin/delete_judge.php with a malicious judge_id value. Because the public exploit demonstrates the technique, scanning tools and automated bots can identify and weaponize vulnerable hosts quickly. The endpoint resides under /admin/, but exploitation does not require valid administrator credentials when access controls on the script are missing or misconfigured. See the VulDB Vulnerability Detail #365547 and the GitHub Issue Discussion for the publicly available technical write-up.

Detection Methods for CVE-2026-9528

Indicators of Compromise

HTTP requests to /admin/delete_judge.php containing SQL metacharacters such as single quotes, UNION, SLEEP(, BENCHMARK(, or comment sequences in the judge_id parameter
Unexpected DELETE, UNION SELECT, or information_schema queries originating from the web application database user
Web server access logs showing repeated requests to delete_judge.php from a single source with varying parameter payloads

Detection Strategies

Inspect web server and application logs for judge_id values that are not strictly numeric
Deploy a web application firewall rule that blocks SQL injection signatures targeting administrative PHP scripts
Enable database query logging and alert on queries referencing information_schema, mysql.user, or stacked statements from the application account

Monitoring Recommendations

Monitor for spikes in 500-series HTTP responses from /admin/delete_judge.php, which often indicate injection probing
Track authentication anomalies and unexpected administrative account creation in the application database
Correlate outbound connections from the web host with database error events to surface successful exfiltration attempts

How to Mitigate CVE-2026-9528

Immediate Actions Required

Restrict network access to the /admin/ directory to trusted management IP ranges using web server access controls
Enforce authentication checks on delete_judge.php and verify the caller holds an administrator session before executing any database operation
Deploy a WAF rule that rejects non-integer values for the judge_id parameter

Patch Information

No vendor patch has been published for itsourcecode Electronic Judging System 1.0 at the time of writing. Operators should monitor the ITSourceCode website for updated releases and apply source-level fixes by replacing string-concatenated SQL with prepared statements using PDO or mysqli parameter binding.

Workarounds

Modify delete_judge.php to cast judge_id to an integer with intval() before use, or replace the query with a prepared statement binding the value as an integer
Apply least-privilege permissions to the database account used by the application so it cannot read system tables or write outside its schema
Take the application offline if administrative access cannot be restricted to trusted networks until a code-level fix is applied

bash

# Example Apache configuration to restrict /admin/ access
<Location "/admin/">
    Require ip 10.0.0.0/8
    Require ip 192.168.0.0/16
</Location>