Dozzle is a tool designed to provide real-time log viewing for Docker containers, often used in development and production environments to monitor containerized applications. The vulnerability identified as CVE-2026-24740 stems from improper access control in Dozzle's agent-backed shell endpoints. Specifically, Dozzle implements label-based filtering to restrict user access to containers (e.g., users may only view containers labeled with `env=dev`). However, prior to version 9.0.3, this filtering mechanism could be bypassed by directly specifying container IDs, allowing an attacker with limited permissions to access containers outside their authorized scope, such as those labeled `env=prod`. Exploiting this flaw grants the attacker an interactive root shell within these out-of-scope containers on the same host, effectively escalating privileges and breaching container isolation. The vulnerability does not require user interaction and can be exploited remotely over the network, with no authentication required beyond the initial restricted access. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no user interaction. The flaw relates to CWE-284 (Improper Access Control) and CWE-863 (Incorrect Authorization). The vendor addressed the issue in Dozzle version 9.0.3 by patching the access control checks to enforce label restrictions properly and prevent container ID-based bypasses.

For European organizations, this vulnerability poses significant risks, especially those relying on Docker containerization and using Dozzle for log monitoring. Unauthorized root shell access to containers can lead to full compromise of container workloads, data exfiltration, lateral movement within the host, and potential disruption of critical services. Confidential information within containers can be exposed or altered, and attackers may deploy malicious payloads or pivot to other systems. Organizations in sectors with stringent data protection requirements, such as finance, healthcare, and critical infrastructure, face heightened regulatory and operational risks. The vulnerability's ease of exploitation and high impact on container security could undermine trust in containerized environments and complicate compliance with European data protection laws like GDPR. Additionally, the shared host environment typical in container deployments means that a single compromised container could jeopardize other containers and the host system itself.

The primary and most effective mitigation is to upgrade Dozzle to version 9.0.3 or later, where the access control flaw has been patched. Organizations should audit their container monitoring tools to identify any instances of Dozzle running vulnerable versions. Until upgrades are applied, restrict network access to Dozzle endpoints to trusted users and networks only, using firewalls or network segmentation to limit exposure. Implement strict container runtime security policies to monitor and restrict shell access within containers. Employ container isolation best practices, such as using separate hosts for different environments (e.g., dev and prod) to reduce risk from cross-environment attacks. Regularly review and enforce least privilege principles for users accessing container management and monitoring tools. Additionally, monitor logs and network traffic for suspicious activity indicative of unauthorized container access attempts. Finally, integrate vulnerability management processes to ensure timely patching of container-related tools.