CVE-2026-49869: Kestra OSS /configs suffix auth bypass to unauthenticated RCE

Exploited in the wild Critical 10.0 EPSS 2.1%

Kestra OSS's AuthenticationFilter exempted any API path ending in '/configs' from Basic Auth, so an unauthenticated attacker can create and run a flow named 'configs' (e.g. PUT /api/v1/main/flows/<ns>/configs then POST /api/v1/main/executions/<ns>/configs). Because script plugins are enabled by default, this gives remote code execution as root inside the Kestra worker container, plus KV-secret writes and log/flow deletion. Fixed in Kestra 1.0.45 and 1.3.21; CISA added it to the Known Exploited Vulnerabilities catalog on 2026-09-02.

CVE-2026-49869CVE identifier
10.0CVSS 3.1 base score (critical)
2026-09-02added to CISA's exploited list (US federal deadline 2026-09-05)
2.1%EPSS: chance of exploitation in the next 30 days (higher than 82% of CVEs)
2026-06-26published

What do these terms mean? CVE · CVSS score · exploited (KEV) · EPSS · backported fix · all terms

What to do now

Check whether you run the affected software and which version (commands below).
Install the fixed version for your system: see “Patch it” below.
Recreate/restart all Kestra server and worker containers on the new image.
Because this flaw is being exploited, also check the server for signs of compromise.

Affected and fixed versions

Affected:

Kestra OSS before 1.0.45
Kestra OSS 1.1.0 before 1.3.21

Fixed in:

Kestra 1.0.45
Kestra 1.3.21

Patch it

Use the commands for your system. Distribution packages often keep an older version number with the fix backported, so compare with the fixed package versions in the table below, not only with the upstream version.

Docker images

docker pull kestra/kestra:v1.3.21   # or v1.0.45 on the 1.0 line, or later
# recreate the containers (docker compose up -d)

General update steps for every system are on the Linux and Unix & BSD pages; after updating, see which services to restart.

Look for signs of exploitation

API requests to paths ending in /configs other than GET /api/v1/configs and GET /api/v1/{tenant}/configs, e.g. PUT /api/v1/main/flows/<namespace>/configs, POST /api/v1/main/executions/<namespace>/configs, PUT .../namespaces/<ns>/kv/configs (per the advisory's bypassed routes).
Unexpected flows or KV entries named 'configs', and deleted flows, dashboards or logs.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/kestra-io/kestra/security/advisories/GHSA-5vc5-wxxq-3fjx ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-49869

Sources

Page generated automatically from official sources on 2026-11-03 18:05 UTC and reviewed by an editor. Always confirm with your vendor's advisory.