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CVE-2026-53576

Kestra: Unauthenticated RCE via /configs path-suffix auth-filter bypass

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 1.0.45, 1.3.21
3 proofs of concept on GitHub, 1 Nuclei template
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: total

Summary

Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the authentication filter for the REST API (@Filter("/api/v1/**")) treats any request whose path ends in /configs as the public instance-config endpoint and forwards it without a credential check. kestra addresses its resources by URL path segments that the caller chooses (/api/v1/{tenant}/flows/{namespace}, /api/v1/{tenant}/executions/{namespace}/{id}, /api/v1/{tenant}/namespaces/{namespace}/kv/{key}). An anonymous caller picks the literal configs as the final segment, and the request bypasses Basic-Auth entirely. Because the bypass reaches the flow-create and execution-trigger routes, an unauthenticated caller creates a flow containing a Shell or Process task and runs it. The task executes as root inside the kestra container. The official docker-compose.yml mounts /var/run/docker.sock, so root in the container reaches the host Docker daemon. This vulnerability is fixed in 1.0.45 and 1.3.21.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • kestra-io kestra

    fixed in 1.0.45; From 1.1.0 · fixed in 1.3.21

References 5

GitHub · kestra-io/kestra

GitHub · projectdiscovery/nuclei-templates

GitHub · AtlasVector/Kestra-cve-2026-53576

GitHub · TamatahYT/CVE-2026-53576

GitHub · emitsco768/Vulnerability-lab-cve-2026-53576