CVE-2026-1535: Fabian Online Music Site SQLi Vulnerability

CVE-2026-1535 Overview

CVE-2026-1535 is a SQL injection vulnerability in code-projects Online Music Site 1.0, published by Fabian. The flaw resides in the /Administrator/PHP/AdminReply.php endpoint, where the ID parameter is concatenated into a SQL query without proper sanitization. Attackers can manipulate the ID argument to inject arbitrary SQL statements. The vulnerability is exploitable remotely over the network and requires no authentication or user interaction. Public disclosure has occurred through a GitHub issue report and VulDB submission, increasing the likelihood of opportunistic exploitation against exposed installations.

Critical Impact

Unauthenticated remote attackers can inject SQL via the ID parameter in AdminReply.php, potentially reading or modifying database contents in the Online Music Site application.

Affected Products

• Fabian Online Music Site 1.0
• code-projects Online Music Site (administrative module)
• Deployments exposing /Administrator/PHP/AdminReply.php to untrusted networks

Discovery Timeline

• 2026-01-28 - CVE-2026-1535 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-1535

Vulnerability Analysis

The vulnerability is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The affected component is the administrative reply handler at /Administrator/PHP/AdminReply.php within the Online Music Site 1.0 codebase. The handler accepts an ID request parameter and incorporates it directly into a backend SQL query.

Because the parameter is not parameterized or escaped, attackers can break out of the intended query context. Injected payloads can append UNION SELECT statements, boolean conditions, or stacked queries depending on the underlying database driver configuration. The result is unauthorized read or write access to the application database.

Root Cause

The root cause is the use of unsanitized user-supplied input in dynamic SQL construction. The AdminReply.php script does not apply prepared statements or input validation to the ID argument before passing it to the database layer. This pattern is common in PHP applications that rely on string concatenation with the legacy mysql_* or unparameterized mysqli_* APIs.

Attack Vector

Exploitation requires only network access to the administrative endpoint. The attacker issues an HTTP request to /Administrator/PHP/AdminReply.php with a crafted ID value containing SQL metacharacters. No credentials or user interaction are required, per the published CVSS vector. A proof-of-concept has been disclosed in the linked GitHub Issue Report and VulDB #343221.

// No verified exploit code is published in the referenced advisories.
// The vulnerability is triggered by supplying SQL metacharacters
// in the ID parameter of a request to /Administrator/PHP/AdminReply.php.

Detection Methods for CVE-2026-1535

Indicators of Compromise

• HTTP requests to /Administrator/PHP/AdminReply.php containing SQL metacharacters such as ', ", --, UNION, SELECT, or SLEEP( in the ID parameter.
• Database error messages or anomalous response sizes returned from AdminReply.php requests.
• Unexpected administrative actions or reply records created without a corresponding authenticated session.

Detection Strategies

• Inspect web server access logs for repeated requests to AdminReply.php with non-numeric ID values or URL-encoded SQL syntax.
• Deploy a web application firewall (WAF) rule that flags SQL injection patterns targeting the ID query string parameter.
• Correlate database audit logs against application logs to surface queries originating from AdminReply.php that reference unexpected tables.

Monitoring Recommendations

• Enable verbose request logging for the /Administrator/ directory and forward logs to a centralized SIEM.
• Alert on outbound database connections returning large result sets following requests to AdminReply.php.
• Monitor for new or modified rows in administrative tables outside scheduled maintenance windows.

How to Mitigate CVE-2026-1535

Immediate Actions Required

• Restrict network access to the /Administrator/ path using IP allowlisting or VPN-only access until a fix is applied.
• Audit AdminReply.php and adjacent administrative scripts for use of unparameterized SQL queries.
• Review database logs for evidence of prior exploitation against the ID parameter.

Patch Information

No vendor patch is referenced in the NVD entry for CVE-2026-1535. Operators should track the GitHub Issue Report and the VulDB CTI ID #343221 for remediation updates. Until an official fix is released, apply source-level mitigation by replacing string concatenation with prepared statements using mysqli::prepare or PDO parameter binding.

Workarounds

• Add server-side input validation to enforce that ID is a strictly numeric value before it reaches the SQL query.
• Deploy a WAF signature blocking SQL injection payloads against the AdminReply.php endpoint.
• Apply the principle of least privilege to the database account used by the application, removing DROP, ALTER, and FILE permissions.

# Example ModSecurity rule to block SQLi attempts against AdminReply.php
SecRule REQUEST_URI "@contains /Administrator/PHP/AdminReply.php" \
    "chain,phase:2,deny,status:403,id:1026001535,msg:'Possible SQLi against AdminReply.php ID parameter'"
SecRule ARGS:ID "@rx (?i)(union(.*?)select|sleep\(|--|;|')" "t:urlDecodeUni,t:lowercase"