Apply patches released by Langflow and Ruby on Rails maintainers immediately. Monitor system logs for unusual Python execution or unexpected process behavior. Implement network segmentation and restrict inbound access to Langflow deployments. Update Ruby on Rails applications to the latest secure version. Review and harden credential management practices.
Quick answers
What is CVE-2026-66066?
Apply patches released by Langflow and Ruby on Rails maintainers immediately. Monitor system logs for unusual Python execution or unexpected process behavior. Implement network segmentation and restrict inbound access to Langflow deployments. Update Ruby on Rails applications to the latest secure version. Review and harden credential management practices.
How severe is CVE-2026-66066?
critical, CVSS 9.8
Is CVE-2026-66066 known to be exploited?
It is not marked known-exploited in this record.
How should CVE-2026-66066 be mitigated?
Apply patches released by Langflow and Ruby on Rails maintainers immediately. Monitor system logs for unusual Python execution or unexpected process behavior. Implement network segmentation and restrict inbound access to Langflow deployments. Update Ruby on Rails applications to the latest secure version. Review and harden credential management practices.
CVSS
9.8
Vendor
Langflow
Published
Sep 30, 2026 · 08:05
Patch
Unknown / not confirmed
Affected products
Langflow, Ruby on Rails
Mitigation
Apply patches released by Langflow and Ruby on Rails maintainers immediately. Monitor system logs for unusual Python execution or unexpected process behavior. Implement network segmentation and restrict inbound access to Langflow deployments. Update Ruby on Rails applications to the latest secure version. Review and harden credential management practices.
According to VulnCheck, threat actors are actively exploiting two critical vulnerabilities: CVE-2026-0768 in Langflow, which lacks input validation and could allow arbitrary Python code execution as root, and CVE-2026-66066 in Ruby on Rails. The full details of the Rails flaw were truncated in initial reporting, but both flaws are assessed as critical and have been weaponized in the wild for credential-probing and command-and-control activity.
