CVE-2026-49869: Kestra OSS OS Command Injection Vulnerability
Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, AuthenticationFilter in Kestra OSS uses request.getPath().endsWith("/configs") to whitelist the public configuration endpoint from Basic Auth. Because the check is a suffix match rather than an exact path match, any API path whose last segment is configs bypasses authentication entirely. An unauthenticated remote attacker can exploit this to create and execute arbitrary workflows without credentials. Because Kestra ships with script execution plugins (plugin-script-shell, plugin-script-python, etc.) enabled by default, this directly results in unauthenticated Remote Code Execution as root inside the Kestra worker container. This vulnerability is fixed in 1.0.45 and 1.3.21.
Other sources
Kestra OSS contains an OS command injection vulnerability that could allow an unauthenticated remote attacker to create and execute arbitrary workflows without credentials.
— CISA
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Kestra OSSto a version that resolves this vulnerability.Fixed in 1.0.45 - Upgrade
Upgrade
Kestra OSSto a version that resolves this vulnerability.Fixed in 1.3.21 - Configuration
Update AuthenticationFilter so the public configuration endpoint is matched exactly (not via suffix/endsWith on the final path segment), preventing authentication bypass for any API path whose last segment is "configs".
Kestra OSS AuthenticationFilter request.getPath().endsWith("/configs") = Replace suffix match with exact path match for the public configuration endpoint - Compensating control
If mitigations are unavailable, discontinue use of the Kestra product (evaluate internet exposure per CISA BOD 26-04 for cloud services).
- Compensating control
Because script execution plugins (e.g., plugin-script-shell, plugin-script-python) are enabled by default, disable these script execution plugins if not required to reduce unauthenticated RCE risk inside the Kestra worker container.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-49869?
The severity of CVE-2026-49869 is rated as critical with a score of 10.
How do I fix CVE-2026-49869?
To fix CVE-2026-49869, upgrade to Kestra version 1.0.45 or 1.3.21 or later.
What type of vulnerability is CVE-2026-49869?
CVE-2026-49869 is an unauthenticated remote code execution vulnerability caused by an authentication bypass.
Which versions of Kestra are affected by CVE-2026-49869?
Kestra versions prior to 1.0.45 and 1.3.21 are affected by CVE-2026-49869.
What kind of exploitation is possible with CVE-2026-49869?
CVE-2026-49869 allows attackers to execute arbitrary code remotely due to authentication bypass in the AuthenticationFilter.