CVE-2026-25125: October CMS Information Disclosure Flaw

CVE-2026-25125 Overview

October CMS, a popular Content Management System and web platform built on Laravel, contains a server-side information disclosure vulnerability in its INI settings parser. The vulnerability stems from PHP's parse_ini_string() function supporting ${} syntax for environment variable interpolation. Attackers with Editor access can inject patterns such as ${APP_KEY} or ${DB_PASSWORD} into CMS page settings fields, causing sensitive environment variables to be resolved, stored in the template, and returned to the attacker when the page is reopened.

Critical Impact

This vulnerability enables exfiltration of sensitive credentials and secrets including database passwords, AWS keys, and application keys, potentially leading to further attacks such as database access or cookie forgery.

Affected Products

• October CMS versions prior to 3.7.14
• October CMS versions prior to 4.1.10
• Installations with cms.safe_mode enabled

Discovery Timeline

• 2026-04-14 - CVE CVE-2026-25125 published to NVD
• 2026-04-14 - Last updated in NVD database

Technical Details for CVE-2026-25125

Vulnerability Analysis

This vulnerability is classified under CWE-94 (Improper Control of Generation of Code) and represents a server-side information disclosure issue. The attack requires network access and high privileges (Editor role), but once those conditions are met, an attacker can achieve high confidentiality impact by extracting sensitive environment variables stored on the server.

The vulnerability specifically targets the INI settings parser functionality within October CMS. When cms.safe_mode is enabled, the CMS relies on this parser to handle page configuration securely without allowing direct PHP execution. However, the underlying parse_ini_string() PHP function inherently supports environment variable interpolation through the ${} syntax, creating an unintended information disclosure channel.

Root Cause

The root cause lies in PHP's native parse_ini_string() function behavior, which automatically resolves environment variable references using the ${} syntax. When October CMS processes page settings through this function, it inadvertently allows users with Editor privileges to inject environment variable reference patterns. These patterns are resolved server-side during parsing, and the resulting values (containing sensitive data) are stored in the template and exposed when the page is subsequently accessed or edited.

Attack Vector

The attack vector requires an authenticated user with Editor-level access to the October CMS backend. The attacker crafts malicious input containing environment variable interpolation patterns (e.g., ${APP_KEY}, ${DB_PASSWORD}, ${AWS_SECRET_ACCESS_KEY}) and injects these into CMS page settings fields.

When the INI parser processes these settings, PHP's parse_ini_string() function resolves the ${} patterns against actual server environment variables. The resolved values are then stored in the template data. When the attacker (or any editor) reopens the page settings, the previously-injected patterns now display the actual environment variable values, completing the information exfiltration.

This vulnerability is only exploitable when cms.safe_mode is enabled, as disabling safe mode already permits direct PHP code injection, making this particular attack vector irrelevant.

Detection Methods for CVE-2026-25125

Indicators of Compromise

• Unusual ${} patterns appearing in CMS page settings or template configurations
• Editor-level users querying or modifying page settings at abnormal frequencies
• Database records containing environment variable reference syntax in page configuration fields
• Unexpected access to pages by users immediately after settings modifications

Detection Strategies

• Implement logging and alerting for page settings modifications containing ${} or similar interpolation patterns
• Review CMS audit logs for Editor users accessing or modifying multiple page settings in quick succession
• Monitor for database queries that may indicate extraction of page template data
• Deploy application-layer monitoring to detect environment variable patterns in user-controllable input fields

Monitoring Recommendations

• Enable comprehensive audit logging for all CMS backend administrative actions
• Configure alerts for any attempts to save page settings containing environment variable interpolation syntax
• Periodically audit Editor role assignments to ensure only trusted personnel have access
• Monitor web server logs for unusual patterns of page retrieval following settings modifications

How to Mitigate CVE-2026-25125

Immediate Actions Required

• Upgrade October CMS to version 3.7.14 or later (for 3.x branch)
• Upgrade October CMS to version 4.1.10 or later (for 4.x branch)
• Review all Editor-level account assignments and restrict access to fully trusted administrators only
• Audit existing page settings for any ${} patterns that may indicate prior exploitation attempts

Patch Information

October CMS has released security patches addressing this vulnerability in versions 3.7.14 and 4.1.10. The fix prevents environment variable interpolation patterns from being processed and resolved by the INI settings parser. Organizations should prioritize upgrading to these patched versions immediately.

For detailed patch information, refer to the GitHub Security Advisory.

Workarounds

• Restrict Editor tool access exclusively to fully trusted administrators until patches can be applied
• Ensure database and cloud service credentials are not accessible from the web server's network segment
• Consider temporarily disabling the ability to modify page settings if immediate patching is not feasible
• Implement network segmentation to limit the impact of potential credential exfiltration

# Example: Restricting Editor permissions in October CMS configuration
# Review and audit backend user roles
php artisan october:up

# Verify cms.safe_mode is properly configured
# In config/cms.php, ensure safe_mode is set appropriately
# 'safe_mode' => true,

# After upgrading, clear application caches
php artisan cache:clear
php artisan config:clear