The flaw is in Flyto2 Core’s workflow engine variable resolver, which expands any ${env.VAR} reference without enforcing an allowlist or capability policy. Attacker‑supplied workflow parameters can therefore bypass the default denylist for env.get and env.load_dotenv, enabling the exfiltration of sensitive environment secrets through permitted modules. This results in confidentiality compromise of data that should remain hidden from workflows. The weakness corresponds to CWE‑522 (Sensitive Data Exposure), CWE‑668 (Information Exposure Through Log Files) and CWE‑693 (Missing Operational Transparency).

Flyto2 Core version 2.26.5 and earlier are affected. The vulnerability is present in the flytohub:flyto-core product; only releases starting at 2.26.6 contain the fix. System administrators using any Flyto2 Core instance before 2.26.6 should review version usage.

The CVSS score of 8.6 indicates high severity, yet the EPSS score of less than 1 % suggests a low probability of exploitation at present, and the vulnerability is not listed in CISA’s KEV catalog. The likely attack vector is via a crafted workflow or automation script that injects ${env.VAR} references; if such workflows are accessible from untrusted input or remote interfaces, an attacker could obtain arbitrary environment secrets. System‑wide integrity is threatened if the impacted environment variables include credentials or keys, as the workflow can read and transmit them through allowed modules.