Fission runtime pods were created with the ServiceAccountName fission‑fetcher, which has cluster‑level permission to read all secrets and configmaps in the namespace. The runtime pod’s automated token was mounted into the user’s function container, allowing any function code executed in that container to use the fission‑fetcher API token and read or enumerate any secret or configmap within the namespace. This results in privileged access to sensitive data beyond the Function.spec.secrets allow‑list that users intend to expose. The weakness is a combination of improper privilege assignment (CWE‑250, CWE‑269) and insecure default configuration (CWE‑538).

The vulnerability affects all releases of the Fission open‑source serverless framework prior to version 1.23.0. Administrators using earlier versions should verify their installation and plan an update to mitigate the issue.

The vulnerability carries a CVSS base score of 8.7, indicating high severity. The EPSS score is currently unavailable, and the issue is not listed in the CISA KEV catalog. The attack vector requires that an attacker can supply or alter function code within the cluster; once inside the function container, the attacker can read any secret or configmap exposed in the namespace. The risk is significant for environments that rely on strict namespace isolation for secrets protection.