CVE-2026-53576CWE-288CWE-94

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

Critical · published June 26, 2026

CVSS v3.1
10.0
EPSS
3%
Percentile
88.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
10.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.03296 · 88.4th percentile
Weaknesses
CWE-288 · Authentication Bypass Using an Alternate Path or Channel; CWE-94 · Improper Control of Generation of Code ('Code Injection')
Published
2026-06-26T20:54Z
EPSS history
Timeline
  • 26 JUN 20:54Z
    Kestra: Unauthenticated RCE via /configs path-suffix auth-filter bypass
    cvelistv5