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Fencer Intel
critical 10.0

CVE-2026-53576 json

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

published 4mo ago modified 17d ago also EUVD-2026-39919

cvss
10.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.3%
EPSS 3.3% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

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.

Patch / fix

  • io.kestra kestra 1.0.45, 1.3.21
  • kestra kestra 1.0.45, 1.3.21

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
4mo ago

Exploit prediction

3.30% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/kestra-io/kestra/security/advisories/GHSA-2q47-568g-9h4f referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

  • kestra-io kestra

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code
  • CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.