CVE-2026-18592 Overview
CVE-2026-18592 is a SQL injection vulnerability in osCommerce 4.14.63493. The flaw resides in the EmailController function within app/lib/backend/controllers/EmailController.php, part of the Email Template Configuration component. Attackers can manipulate the email_templates_key argument to inject arbitrary SQL statements against the backend database. The issue is exploitable remotely and requires high privileges on the target application. A public exploit has been released, increasing the risk of opportunistic abuse. The vendor was contacted prior to disclosure but did not respond.
Critical Impact
Authenticated remote attackers can inject SQL through the email_templates_key parameter, resulting in unauthorized access to backend database contents and limited integrity and availability impact.
Affected Products
- osCommerce 4.14.63493
- Component: Email Template Configuration (app/lib/backend/controllers/EmailController.php)
- Function: EmailController
Discovery Timeline
- 2026-08-03 - CVE-2026-18592 published to NVD
- 2026-08-03 - Last updated in NVD database
Technical Details for CVE-2026-18592
Vulnerability Analysis
The vulnerability is classified under [CWE-74] Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). The EmailController in osCommerce 4.14.63493 accepts the email_templates_key parameter and passes it into a database query without sufficient sanitization or parameterization. Because the input is embedded directly in SQL, an authenticated attacker can alter the query's logic. Reporting from the linked Open Science advisory describes this as a second-order SQL injection, meaning the tainted value is stored first and later reintroduced into a query, bypassing naive input filters that only inspect first-order requests.
Root Cause
The root cause is missing parameterization when email_templates_key is used to construct a SQL statement inside EmailController.php. The application trusts previously stored template-key values on retrieval, so a malicious payload written to storage during template configuration is later concatenated into a query verbatim. This eliminates the isolation between data and code that prepared statements enforce.
Attack Vector
Exploitation occurs over the network against the osCommerce backend. The attacker must possess high-privilege backend credentials to reach the Email Template Configuration functionality. Once authenticated, the attacker submits a crafted email_templates_key value that stores an SQL fragment. When the backend later queries the stored key, the injected SQL is executed against the database, exposing information from the affected tables and permitting limited modification.
A proof-of-concept has been published and referenced in the Open Science SQLi Report and VulDB CVE-2026-18592. No verified exploit code is reproduced here.
Detection Methods for CVE-2026-18592
Indicators of Compromise
- Backend HTTP requests to email template configuration endpoints containing SQL metacharacters such as ', --, UNION, SELECT, or SLEEP( inside the email_templates_key parameter.
- Database entries in the email templates table where the key column contains SQL syntax rather than a normal identifier value.
- Web server access logs showing repeated backend requests from a single authenticated administrative session targeting EmailController.php.
Detection Strategies
- Enable database query logging and alert on anomalous queries originating from the email template code path, particularly queries containing operators like UNION SELECT or comment sequences.
- Deploy a Web Application Firewall (WAF) rule that inspects parameter values submitted to backend osCommerce routes for SQL injection signatures.
- Correlate administrator authentication events with subsequent modifications to email template records to identify credential misuse.
Monitoring Recommendations
- Monitor for outbound database errors returned to the browser that reveal SQL syntax, structure, or stack traces, which frequently accompany injection probing.
- Track privileged osCommerce backend sessions and alert on unusual write activity to configuration tables outside change windows.
- Baseline the volume of requests to app/lib/backend/controllers/EmailController.php and flag deviations that may indicate automated exploitation attempts.
How to Mitigate CVE-2026-18592
Immediate Actions Required
- Restrict backend administrative access to trusted IP ranges and enforce multi-factor authentication for all osCommerce administrator accounts.
- Rotate database and administrator credentials if unusual activity is observed against the email template configuration.
- Audit the email templates table for entries containing SQL syntax and remove any suspicious values.
Patch Information
At the time of publication, no vendor patch has been released. The vendor did not respond to disclosure, according to the VulDB CVE-2026-18592 entry. Monitor the osCommerce project for future security updates and apply them once available.
Workarounds
- Apply a virtual patch via WAF that rejects email_templates_key values containing SQL metacharacters or exceeding an expected numeric or alphanumeric format.
- Temporarily disable the Email Template Configuration feature or remove administrative access to it until a fix is available.
- Modify app/lib/backend/controllers/EmailController.php locally to use parameterized queries or an ORM binding for the email_templates_key value.
- Enforce least-privilege database accounts so the web application user cannot read or modify tables outside its required scope.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
