CVE-2026-90525: Sales and Inventory System SQL Injection

CVE-2026-90525 is a SQL injection vulnerability in itsourcecode Sales and Inventory System 1.0 affecting the cust_pos_trans.php file. Attackers can exploit the firstname parameter remotely to compromise database integrity. This article covers technical details, affected versions, impact assessment, and mitigation strategies.

CVE-2026-90525 Overview

CVE-2026-90525 is a SQL injection vulnerability in itsourcecode Sales and Inventory System version 1.0. The flaw resides in the /pages/cust_pos_trans.php file, where the firstname parameter is passed to a database query without proper sanitization. An authenticated remote attacker can manipulate the parameter to inject arbitrary SQL statements. The weakness is classified under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component. A public exploit has been disclosed, increasing the likelihood of opportunistic abuse against exposed installations.

Critical Impact
Remote attackers with low-privilege access can inject SQL through the firstname parameter to read, modify, or delete data in the underlying database of the Sales and Inventory System.

Affected Products

itsourcecode Sales and Inventory System 1.0
Vulnerable component: /pages/cust_pos_trans.php
Vulnerable parameter: firstname

Discovery Timeline

2026-09-13 - CVE-2026-90525 published to NVD
2026-09-20 - Last updated in NVD database

Technical Details for CVE-2026-90525

Vulnerability Analysis

The vulnerability affects the customer point-of-sale transaction handler in the Sales and Inventory System. The cust_pos_trans.php script accepts a firstname argument from the HTTP request and concatenates it directly into an SQL statement executed against the backend database. Because the input is not sanitized, escaped, or bound as a parameter, an attacker can break out of the intended query context and append arbitrary SQL clauses. Exploitation requires network access to the application and a low-privilege account, but no user interaction. According to the vendor references, a public proof of concept has been made available, lowering the barrier for attackers to weaponize the flaw. Successful exploitation gives an attacker limited but meaningful access to confidentiality, integrity, and availability of stored data.

Root Cause

The root cause is improper neutralization of special elements in a downstream component [CWE-74]. The application constructs SQL queries using string concatenation with user-supplied input from the firstname field rather than using prepared statements or parameterized queries. Any single quote, semicolon, or SQL keyword introduced in the parameter is interpreted by the database engine as part of the query.

Attack Vector

The attack vector is network-based. An authenticated user submits a crafted HTTP request to /pages/cust_pos_trans.php with a malicious value in the firstname parameter. The injected payload can perform UNION-based extraction, boolean-based inference, or time-based blind exfiltration against the underlying database. See the VulDB entry for CVE-2026-90525 and the associated issue tracker for technical detail on the exposed parameter.

// No verified exploit code is reproduced here. Refer to the linked
// VulDB entry and public issue tracker for the disclosed proof of concept.

Detection Methods for CVE-2026-90525

Indicators of Compromise

HTTP POST or GET requests to /pages/cust_pos_trans.php containing SQL metacharacters (', --, ;, UNION, SELECT) in the firstname parameter.
Web server access logs showing unusually long firstname values or encoded payloads such as %27 and %20OR%201=1.
Database error messages or stack traces referencing the cust_pos_trans code path returned to clients.

Detection Strategies

Deploy web application firewall (WAF) signatures that identify SQL injection patterns targeting POS transaction endpoints.
Enable database query logging and alert on syntactically anomalous queries originating from the Sales and Inventory application user.
Correlate authentication events with subsequent request bursts to cust_pos_trans.php to identify low-privilege accounts probing the parameter.

Monitoring Recommendations

Monitor for repeated 4xx or 5xx responses from /pages/cust_pos_trans.php, which often accompany blind SQL injection probing.
Alert on outbound database traffic spikes and large result sets returned to the application, indicating potential data extraction.
Track new or unusual user-agent strings interacting with the POS transaction endpoint.

How to Mitigate CVE-2026-90525

Immediate Actions Required

Restrict network exposure of the Sales and Inventory System to trusted internal networks or via VPN until a fix is applied.
Disable or tightly control low-privilege accounts that can reach /pages/cust_pos_trans.php.
Deploy WAF rules blocking SQL metacharacters in the firstname parameter as a virtual patch.

Patch Information

At the time of publication, no vendor patch was linked in the NVD entry or the referenced IT Source Code homepage. Administrators should monitor the vendor site and the VulDB entry for CVE-2026-90525 for updated remediation guidance. Where source access is available, modify cust_pos_trans.php to use parameterized queries (for example, PDO prepared statements) instead of concatenating the firstname value into SQL.

Workarounds

Implement input validation to allow only expected alphanumeric characters in the firstname field.
Enforce least privilege on the database account used by the application so that injected queries cannot access administrative tables.
Place the application behind a reverse proxy or WAF configured with OWASP Core Rule Set SQL injection signatures.

bash

# Example ModSecurity rule to block SQLi patterns in the firstname parameter
SecRule ARGS:firstname "@rx (?i)(\bunion\b.*\bselect\b|--|;|'|\bor\b\s+\d+=\d+)" \
    "id:1029052,phase:2,deny,status:403,msg:'Possible SQLi in firstname (CVE-2026-90525)'"