Dagu patches API path traversal after incomplete prior fix

TL;DR — A %2F-encoded slash path traversal in Dagu’s web API can let an authenticated user escape the DAGs directory via multiple endpoints, despite a prior partial fix.

What happened

Dagu is a workflow engine with a built-in web UI used to manage and execute DAG-based jobs.

CVE-2026-33344 describes an incomplete fix for a prior traversal issue (CVE-2026-27598). Per the CVE record, the earlier fix added ValidateDAGName to CreateNewDAG and rewrote generateFilePath using filepath.Base, which patched the CREATE path. However, the remaining API endpoints — GET, DELETE, RENAME, EXECUTE — still pass the {fileName} URL path parameter to locateDAG without calling ValidateDAGName, allowing %2F-encoded forward slashes in {fileName} to traverse outside the DAGs directory.

Severity is CVSS v3.1 8.1 (High). “Incomplete fix” follow-on CVEs like this matter operationally because they’re easy to miss in patch rollouts (“we already fixed that class”), and they commonly recur where multiple endpoints share a helper that wasn’t consistently guarded.

Who is impacted

• Dagu (dagu-org/dagu) versions >= 2.0.0, < 2.3.1.
• Environments exposing Dagu’s web API where authenticated users can reach the affected endpoints (GET/DELETE/RENAME/EXECUTE) with attacker-controlled {fileName} values.

What to do now

• Follow vendor remediation guidance and apply the latest patched release available at the time of writing.

  "This issue has been patched in version 2.3.1."

• Inventory where dagu is deployed (containers, VM services, internal platforms) and identify instances in the affected range.
• Review how Dagu authentication and authorization are configured for users who can access DAG management endpoints (GET/DELETE/RENAME/EXECUTE), since the CVE impact requires an authenticated caller.
• If you suspect abuse, focus investigation on API requests that include %2F-encoded slashes in {fileName} and correlate with unexpected DAG operations (rename/delete/execute).