Arcane, a Docker management application, prior to version 1.13.0 contains a critical OS command injection vulnerability (CVE-2026-23520) in its updater service. The updater service supports lifecycle labels named com.getarcaneapp.arcane.lifecycle.pre-update and com.getarcaneapp.arcane.lifecycle.post-update, which allow specifying shell commands to run before or after container updates. These label values are passed directly to /bin/sh -c without any sanitization or validation, resulting in improper neutralization of special elements (CWE-78). An attacker with any authenticated user access can create a project via the API and specify malicious commands in these lifecycle labels. When an administrator later triggers a container update, either manually or through scheduled checks, Arcane executes these commands inside the container context, leading to arbitrary command execution. This can result in full system compromise, including data theft, modification, or destruction, and disruption of container services. The vulnerability is critical due to the high impact on confidentiality, integrity, and availability, combined with the ease of exploitation by any authenticated user. The flaw is fixed in Arcane 1.13.0, and users are strongly advised to upgrade. No public exploits have been reported yet, but the vulnerability’s nature makes it a high-risk target for attackers.

For European organizations using Arcane for Docker management, this vulnerability poses a severe risk. Attackers with low privileges can escalate to full system compromise by injecting arbitrary commands executed with administrator-triggered updates. This can lead to data breaches, service outages, and potential lateral movement within networks. Given the criticality of containerized environments in modern IT infrastructures, exploitation could disrupt business operations, compromise sensitive data, and damage organizational reputation. The vulnerability’s ability to affect confidentiality, integrity, and availability simultaneously makes it particularly dangerous. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, face increased compliance risks if exploited. Additionally, the requirement for administrator interaction to trigger updates means insider threat scenarios or social engineering could facilitate exploitation. The absence of known exploits in the wild provides a window for proactive mitigation, but the high CVSS score demands immediate attention.

European organizations should immediately upgrade Arcane to version 1.13.0 or later to remediate this vulnerability. Until the upgrade is applied, restrict authenticated user permissions to prevent unauthorized project creation or modification, especially limiting access to the API for non-administrative users. Implement strict monitoring and alerting on lifecycle label changes and container update triggers to detect suspicious activities. Employ network segmentation to isolate Docker management interfaces and limit access to trusted administrators only. Use multi-factor authentication (MFA) for all users with access to Arcane to reduce the risk of compromised credentials. Conduct regular audits of container lifecycle labels and update processes to ensure no unauthorized commands are present. Additionally, consider implementing runtime security controls and container integrity monitoring to detect anomalous command executions. Educate administrators about the risk of triggering updates without verifying project configurations. Finally, maintain up-to-date backups and incident response plans tailored to container environments to minimize impact if exploitation occurs.