CVE-2026-23885: Medium Vulnerability in AlchemyCMS

Alchemy is an open source content management system engine written in Ruby on Rails. Prior to versions 7.4.12 and 8.0.3, the application uses the Ruby `eval()` function to dynamically execute a string provided by the `resource_handler.engine_name` attribute in `Alchemy::ResourcesHelper#resource_url_proxy`. The vulnerability exists in `app/helpers/alchemy/resources_helper.rb` at line 28. The code explicitly bypasses security linting with `# rubocop:disable Security/Eval`, indicating that the use of a dangerous function was known but not properly mitigated. Since `engine_name` is sourced from module definitions that can be influenced by administrative configurations, it allows an authenticated attacker to escape the Ruby sandbox and execute arbitrary system commands on the host OS. Versions 7.4.12 and 8.0.3 fix the issue by replacing `eval()` with `send()`.

The vulnerability has a CVSS score of 6.4, classified as medium severity. This indicates a significant risk to organizations using affected versions of AlchemyCMS, particularly as the attack vector is local, requiring high privileges to exploit.

Organizations should prioritize patching immediately to mitigate potential risks associated with this vulnerability. Failure to apply the relevant updates could expose systems to unauthorized command execution.

Currently, there is no known public exploit, but the existence of a proof-of-concept on GitHub raises concerns about the potential for exploitation. Security teams should remain vigilant for any developments regarding this vulnerability.

Vulnerability Details

The vulnerability allows authenticated users to execute arbitrary commands due to the dangerous use of `eval()`. The official CVE description delineates the severity and implications of this flaw.

Technical Analysis

The root cause of this vulnerability is the insecure implementation of the `eval()` function, which allows for the execution of arbitrary code based on user input. The attack vector is local, requiring that an attacker already has authenticated access to the application.

Risk & Impact Analysis

Risk to organizations includes the potential for unauthorized command execution on the host OS, leading to data breaches or system compromise. The medium severity score indicates that while the vulnerability is not critical, it still poses a considerable risk, especially in environments where authentication is easily obtainable.

Exploitation Status

Affected Versions

Affected versions include all versions prior to 7.4.12 and 8.0.3. Organizations should upgrade to these versions or later to mitigate the vulnerability.

Mitigation & Remediation

To remediate this vulnerability, organizations should apply the patches provided in the releases for versions 7.4.12 and 8.0.3. If immediate patching is not feasible, organizations may consider implementing additional security measures such as restricting administrative access and monitoring for unusual activity.Organizations can validate remediation effectiveness through penetration testing to identify similar weaknesses.

Detection Guidance

Security teams should monitor logs for any indications of unauthorized command execution attempts and behavioral anomalies that could indicate exploitation of this vulnerability.

AppSecure Threat Intelligence Insight

The long-term significance of this vulnerability highlights the importance of secure coding practices in web applications. Organizations utilizing AlchemyCMS should be aware of the implications of using dangerous functions and ensure they are following best practices in application security.This incident represents a broader trend regarding local vulnerabilities being exploited due to poor coding practices. Security teams should consider this when designing their security posture.For further insights and best practices, organizations can explore resources such as the vulnerability management program and the penetration testing methodology to enhance their security measures.