CVE-2026-58053 Details

A vulnerability in Gitea's act_runner with the Docker backend, specifically in version 0.262.0, allows users to bypass container hardening measures. When workflows are executed on a Docker-backed runner, the runner appends workflow-defined container options to the Docker job container's HostConfig. Although the runner disables the Privileged flag when not needed, it fails to properly sanitize other options that can grant access to host resources. This oversight enables a user to create a job container with host namespaces and extensive capabilities, effectively escaping to the host as root, even with privileged mode turned off.

To address this vulnerability, treat workflow-authored container options as untrusted input. Implement a defensive patch that rejects or allowlists job-level Docker options instead of passing them through unfiltered. Additionally, avoid sharing Docker-backed runners with untrusted repositories.