The vulnerability stems from the FlinkSessionJob jarURI field being unvalidated, enabling a user with ClusterRole create permissions to read any file from the operator pod's local filesystem or request data from any address reachable through Flink's pluggable filesystem layer. This allows Server‑Side Request Forgery (CWE‑918) and local file disclosure (CWE‑552).

Apache Flink Kubernetes Operator versions from 1.3.0 up to, but not including, 1.15.0 are affected. The operator is typically deployed within Kubernetes clusters by organizations using Flink for stream processing.

The risk is medium, as indicated by the CVSS score of 6.5, because the flaw permits remote users to access internal resources and secrets without needing external network connectivity. An attacker can craft a CustomResource with a malicious jarURI and use their create privileges to trigger the vulnerability. The EPSS score is < 1%, and the vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that the attacker can submit a malicious CustomResource to the operator. The lack of input validation and allowlists suggests a significant exploitability. The likely attack vector is a user with ClusterRole create permissions targeting the operator.