CVE-2026-75089: PHPGurukul CMS SQL Injection Vulnerability

CVE-2026-75089 Overview

CVE-2026-75089 is a SQL injection vulnerability in PHPGurukul Complaint Management System 1.0. The flaw resides in the user/check_availability.php file, where the email parameter is passed unsanitized into a database query. Remote attackers can exploit this weakness over the network without authentication or user interaction. A public exploit has been disclosed, increasing the likelihood of opportunistic scanning and mass exploitation. 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 arbitrary SQL statements through the email parameter, leading to disclosure or manipulation of backend database records.

Affected Products

PHPGurukul Complaint Management System 1.0
Component: user/check_availability.php
Vulnerable parameter: email

Discovery Timeline

2026-08-18 - CVE-2026-75089 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-75089

Vulnerability Analysis

The vulnerability is a classic SQL injection reachable through the availability check endpoint of the Complaint Management System. When a client submits a request to user/check_availability.php, the application concatenates the email argument into a SQL query without parameterization or input validation. An attacker can supply crafted SQL fragments as the email value to alter query logic. According to the EPSS data set (0.263%, 18th percentile), automated scanning activity targeting this CVE is currently modest, but the presence of a public proof of concept raises the exploitation prospect over time.

Root Cause

The root cause is improper neutralization of user-supplied input before it is passed to the database layer [CWE-74]. The check_availability.php script accepts the email argument directly from an HTTP request and embeds it in a SQL statement. Because prepared statements or input escaping are not applied, database syntax characters in the parameter modify the intended query. This design flaw is common in legacy PHP applications that build SQL through string concatenation.

Attack Vector

Exploitation is remote and requires no authentication or user interaction. An attacker sends an HTTP request to the vulnerable endpoint with a crafted email parameter containing SQL metacharacters. The injected payload can extract database contents through UNION-based or boolean-based techniques, or exfiltrate data through time-based blind injection. Successful exploitation can expose administrator credentials, complaint records, and other stored data. A public exploit reference is available in the GitHub CVE Issue Discussion.

No verified code examples are available. Refer to the VulDB CVE-2026-75089 Detail advisory for additional technical detail.

Detection Methods for CVE-2026-75089

Indicators of Compromise

HTTP requests to user/check_availability.php containing SQL syntax such as UNION SELECT, SLEEP(, OR 1=1, or quote characters in the email parameter.
Web server access logs showing repeated requests to the availability endpoint from a single source address.
Database error messages referencing MySQL syntax returned in HTTP responses from the endpoint.

Detection Strategies

Deploy web application firewall rules that inspect the email parameter for SQL injection signatures.
Enable database query logging and alert on unexpected query structures originating from the check_availability.php context.
Correlate anomalous request volumes to user/check_availability.php with downstream database read spikes.

Monitoring Recommendations

Monitor authentication log tables for unauthorized read patterns following requests to the vulnerable endpoint.
Alert on outbound data volume anomalies from the database host, which may indicate bulk exfiltration.
Track process telemetry on the web server for unexpected child processes spawned from the PHP interpreter.

How to Mitigate CVE-2026-75089

Immediate Actions Required

Restrict network access to the Complaint Management System until a vendor patch is applied.
Block requests to user/check_availability.php at the reverse proxy or WAF if the endpoint is not required.
Rotate database credentials and audit database contents for evidence of unauthorized access.

Patch Information

No vendor patch has been published in the referenced advisories at the time of writing. Monitor the PHP Gurukul Security Resource and the VulDB Vulnerability Information page for updates. Until a fix is released, treat the application as vulnerable in any production deployment.

Workarounds

Apply a virtual patch through a WAF that rejects non-email-formatted values in the email parameter.
Modify user/check_availability.php to use parameterized queries with PDO or mysqli prepared statements.
Enforce a strict allowlist regex for the email argument before it reaches the database layer.
Run the database account backing the application with least-privilege permissions to limit injection impact.

bash

# Example ModSecurity rule to block SQLi patterns on the vulnerable endpoint
SecRule REQUEST_URI "@contains /user/check_availability.php" \
    "id:1075089,phase:2,deny,status:403,\
     chain,msg:'CVE-2026-75089 SQLi attempt on email parameter'"
    SecRule ARGS:email "@rx (?i)(union(\s|/\*.*\*/)+select|sleep\(|or\s+1=1|--|;)" \
        "t:none,t:urlDecodeUni"