The vulnerability resides in the shared API mode of manga‑image‑translator beta‑0.3 and earlier, where the FastAPI endpoints "/simple_execute/{method}" and "/execute/{method}" use Python’s pickle.loads() to deserialize request bodies without validating the payload. This unsafe deserialization enables any network user who can contact the API to send a specially crafted pickle payload that will be executed with the privileges of the server process. The consequence is full remote code execution on the host, which can compromise confidentiality, integrity, and availability of the affected machine and any services it hosts. The weakness aligns with CWE‑502, indicating insecure deserialization.

The vulnerability affects the manga‑image‑translator application released by zyddnys. Versions beta‑0.3 and earlier running in shared API mode are impacted. No specific minor or patch versions are listed; the issue is present up to and including the latest beta release at the time of the advisory.

CVSS 9.3 reflects a critical severity, yet the EPSS score is below 1 %, indicating that currently the likelihood of exploitation is low. The vulnerability is not yet listed in the CISA KEV catalog. Attackers can reach the vulnerable endpoints over the network; no authentication is required because the intended nonce‑based protection defaults to an empty string, effectively disabling the check. Once accessed, the attacker can inject arbitrary pickled objects that will be deserialized and executed by the server.