CVE-2026-77392 Overview
CVE-2026-77392 is a SQL injection vulnerability in SourceCodester Dynamic Input Field Generator Using HTML, CSS, and PHP version 1.0. The flaw resides in the saveUser function within /public/submit.php. Attackers can manipulate the Researcher argument to inject arbitrary SQL statements against the backend database. The attack is remotely exploitable and a public exploit is available. The weakness maps to CWE-74: Improper Neutralization of Special Elements in Output.
Critical Impact
Remote attackers with low-privileged access can inject SQL statements through the Researcher parameter, potentially exposing or altering database records handled by /public/submit.php.
Affected Products
- SourceCodester Dynamic Input Field Generator Using HTML, CSS, and PHP 1.0
- Component: /public/submit.php
- Vulnerable function: saveUser
Discovery Timeline
- 2026-08-21 - CVE-2026-77392 published to NVD
- 2026-08-24 - Last updated in NVD database
Technical Details for CVE-2026-77392
Vulnerability Analysis
The vulnerability affects the saveUser handler in /public/submit.php, part of the Dynamic Input Field Generator PHP application. The application accepts the Researcher parameter from user-controlled input and passes it into a SQL statement without sufficient sanitization or parameterized query enforcement. Because the application concatenates the tainted value directly into the query, an attacker can break out of the intended string context and append attacker-controlled SQL clauses.
Successful exploitation permits unauthorized reading and modification of database contents accessible to the web application. According to the CVSS 4.0 metrics, exploitation requires network access and low-privileged credentials, with no user interaction required. Public exploit code has been disclosed, increasing the likelihood of opportunistic scanning against exposed instances.
Root Cause
The root cause is improper neutralization of special elements in the SQL query constructed by saveUser. The Researcher argument is concatenated into a query string without prepared statements or input validation, allowing SQL metacharacters such as single quotes, semicolons, and comment tokens to alter query semantics.
Attack Vector
An authenticated attacker submits a crafted HTTP POST request to /public/submit.php with a malicious Researcher value. The injected payload is executed by the database engine during the saveUser call, enabling data extraction through UNION-based or error-based techniques. See the GitHub Gist proof-of-concept and the VulDB entry for CVE-2026-77392 for technical details.
No verified code examples are available. The exploitation mechanism relies on standard SQL injection payloads targeting the Researcher POST parameter.
Detection Methods for CVE-2026-77392
Indicators of Compromise
- HTTP POST requests to /public/submit.php containing SQL metacharacters such as ', --, UNION SELECT, or OR 1=1 in the Researcher field.
- Unexpected database errors logged by the PHP application referencing malformed SQL syntax.
- Anomalous outbound data volumes from the web or database tier following requests to submit.php.
Detection Strategies
- Deploy web application firewall (WAF) rules that flag SQL injection signatures targeting the Researcher parameter on the submit.php endpoint.
- Enable database query logging and alert on structurally unusual queries originating from the application's service account.
- Correlate web access logs with database audit logs to identify request-to-query patterns consistent with injection.
Monitoring Recommendations
- Monitor for repeated failed submissions or 500-series responses from /public/submit.php from a single source IP.
- Alert on database queries returning row counts far exceeding expected values for user creation workflows.
- Track authentication events preceding submission requests to identify low-privileged account abuse.
How to Mitigate CVE-2026-77392
Immediate Actions Required
- Restrict access to /public/submit.php to trusted networks or remove the application from internet exposure until remediated.
- Rotate credentials for the database account used by the application if injection activity is suspected.
- Review database logs for unauthorized SELECT, INSERT, or UPDATE operations originating from the application.
Patch Information
No official vendor patch is referenced in the NVD entry at the time of publication. Consult the SourceCodester project page for updates and community-provided fixes. Application maintainers should replace concatenated SQL with prepared statements using PDO or MySQLi parameter binding for the Researcher argument and all other user-supplied inputs in saveUser.
Workarounds
- Implement server-side input validation that rejects SQL metacharacters in the Researcher field before it reaches the database layer.
- Deploy a WAF rule blocking known SQL injection patterns targeting the submit.php endpoint.
- Apply the principle of least privilege to the application's database user, removing DROP, ALTER, and unnecessary write permissions.
- Refactor saveUser to use parameterized queries (PDO::prepare with bound parameters) rather than string concatenation.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
