CVE-2026-13488: Class Timetabling System SQLi Flaw

CVE-2026-13488 Overview

CVE-2026-13488 is a SQL injection vulnerability in the SourceCodester Class and Exam Timetabling System version 1.0. The flaw resides in the /preview7.php script, where the course_year_section parameter is passed directly into a database query without sanitization. Unauthenticated attackers can exploit the issue remotely over the network by manipulating this parameter. Public exploit details have been released, increasing the likelihood of opportunistic scanning and abuse. The weakness is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). Successful exploitation allows attackers to read, modify, or delete database records used by the timetabling application.

Critical Impact
Unauthenticated remote attackers can inject arbitrary SQL statements through /preview7.php, exposing scheduling and user data stored by the application.

Affected Products

SourceCodester Class and Exam Timetabling System 1.0
/preview7.php endpoint of the application
Deployments exposing the course_year_section parameter to untrusted input

Discovery Timeline

2026-06-28 - CVE-2026-13488 published to NVD
2026-06-29 - Last updated in NVD database

Technical Details for CVE-2026-13488

Vulnerability Analysis

The vulnerability affects the preview7.php component of the SourceCodester Class and Exam Timetabling System 1.0. The script accepts the course_year_section HTTP parameter and concatenates it into a SQL query executed against the backend database. Because the value is not validated, filtered, or bound as a parameter, an attacker can append SQL syntax that alters query logic. The attack requires no authentication and no user interaction, and it can be launched entirely over the network. Public disclosure of the exploit path lowers the barrier for reproduction. According to VulDB and the referenced GitHub issue, proof-of-concept payloads targeting the parameter are already documented.

Root Cause

The root cause is improper neutralization of special elements in a SQL statement [CWE-74]. The application constructs queries using string concatenation with user-controlled input from the course_year_section request parameter. No prepared statements, parameterized queries, or input validation routines are applied before the value reaches the database driver.

Attack Vector

An attacker sends a crafted HTTP request to /preview7.php with a malicious course_year_section value containing SQL metacharacters such as ', --, or UNION SELECT clauses. The injected fragment modifies the executing query, allowing extraction of arbitrary tables, authentication data, or schema information. The attack is remote and unauthenticated.

// Vulnerability described in prose only - no verified exploit code available.
// Refer to the GitHub issue and VulDB entries listed under references
// for technical proof-of-concept details.

Detection Methods for CVE-2026-13488

Indicators of Compromise

HTTP requests to /preview7.php containing SQL metacharacters such as ', ", --, ;, or UNION in the course_year_section parameter.
Unusual database error messages returned in HTTP responses from the timetabling application.
Anomalous outbound queries or large result sets originating from the PHP application's database user.

Detection Strategies

Deploy Web Application Firewall (WAF) signatures targeting SQL injection patterns in the course_year_section parameter.
Enable database query logging and alert on statements referencing information_schema, sleep(), or stacked queries from the timetabling app.
Review web server access logs for repeated requests to /preview7.php with encoded payloads or long parameter values.

Monitoring Recommendations

Correlate web request logs with database audit trails to identify injected query fragments reaching the DBMS.
Alert on spikes in 500-series HTTP responses from /preview7.php, which often indicate injection probes.
Monitor for exfiltration behaviors such as unusually large HTTP response bodies from the application host.

How to Mitigate CVE-2026-13488

Immediate Actions Required

Restrict network access to the Class and Exam Timetabling System until a fix is applied, using firewall rules or authentication proxies.
Deploy WAF rules to block SQL metacharacters and known injection payloads targeting the course_year_section parameter.
Rotate database credentials and audit database accounts for signs of unauthorized access.

Patch Information

No official vendor patch has been published for SourceCodester Class and Exam Timetabling System 1.0 at the time of NVD publication. Administrators should track the GitHub Issue Discussion and the VulDB CVE Report for updates. If the application is not business-critical, consider decommissioning the vulnerable deployment.

Workarounds

Modify preview7.php to use parameterized queries or PDO prepared statements for all database calls involving course_year_section.
Apply server-side input validation that restricts course_year_section to an allow-list of expected values (for example, alphanumeric course codes).
Enforce least-privilege database accounts so the web application cannot read or alter tables beyond its scheduling scope.

bash

# Example nginx rule to block obvious SQL metacharacters on the vulnerable endpoint
location = /preview7.php {
    if ($arg_course_year_section ~* "('|\"|--|;|union|select|sleep\()") {
        return 403;
    }
    # pass to PHP handler as usual
    include fastcgi_params;
    fastcgi_pass unix:/run/php/php-fpm.sock;
}