Dagu is a workflow engine with a built-in Web user interface. From version 2.0.0 to before version 2.3.1, the fix for CVE-2026-27598 added ValidateDAGName to CreateNewDAG and rewrote generateFilePath to use filepath.Base. This patched the CREATE path. The remaining API endpoints - GET, DELETE, RENAME, EXECUTE - all pass the {fileName} URL path parameter to locateDAG without calling ValidateDAGName. %2F-encoded forward slashes in the {fileName} segment traverse outside the DAGs directory. This issue has been patched in version 2.3.1.

Dagu is a workflow engine with a built-in Web user interface. Prior to 2.2.4, the dagRunId request field accepted by the inline DAG execution endpoints is passed directly into filepath.Join to construct a temporary directory path without any format validation. Go's filepath.Join resolves .. segments lexically, so a caller can supply a value such as ".." to redirect the computed directory outside the intended /tmp/<name>/<id> path. A deferred cleanup function that calls os.RemoveAll on that directory then runs unconditionally when the HTTP handler returns, deleting whatever directory the traversal resolved to. With dagRunId set to "..", the resolved directory is the system temporary directory (/tmp on Linux). On non-root deployments, os.RemoveAll("/tmp") removes all files in /tmp owned by the dagu process user, disrupting every concurrent dagu run that has live temp files. On root or Docker deployments, the call removes the entire contents of /tmp, causing a system-wide denial of service. This vulnerability is fixed in 2.2.4.

Dagu is a workflow engine with a built-in Web user interface. Prior to 2.2.4, when Dagu is configured with HTTP Basic authentication (DAGU_AUTH_MODE=basic), all Server-Sent Events (SSE) endpoints are accessible without any credentials. This allows unauthenticated attackers to access real-time DAG execution data, workflow configurations, execution logs, and queue status — bypassing the authentication that protects the REST API. The buildStreamAuthOptions() function builds authentication options for SSE/streaming endpoints. When the auth mode is basic, it returns an auth.Options struct with BasicAuthEnabled: true but AuthRequired defaults to false (Go zero value). The authentication middleware at internal/service/frontend/auth/middleware.go allows unauthenticated requests when AuthRequired is false. This vulnerability is fixed in 2.2.4.

Dagu is a workflow engine with a built-in Web user interface. In versions up to and including 1.16.7, the `CreateNewDAG` API endpoint (`POST /api/v1/dags`) does not validate the DAG name before passing it to the file store. An authenticated user with DAG write permissions can write arbitrary YAML files anywhere on the filesystem (limited by the process permissions). Since dagu executes DAG files as shell commands, writing a malicious DAG to the DAGs directory of another instance or overwriting config files can lead to remote code execution. Commit e2ed589105d79273e4e6ac8eb31525f765bb3ce4 fixes the issue.