There is 1 open security issue in buster.
1 issue left for the package maintainer to handle:
A Denial of Service (DoS) condition is possible in OpenStack Mistral in versions up to and including 7.0.3. Submitting a specially crafted workflow definition YAML file containing nested anchors can lead to resource exhaustion culminating in a denial of service.
You can find information about how to handle this issue in the security team's documentation.