An attacker can send specially crafted data to the add_tool endpoint of Upsonic’s service, which listens on TCP port 7541. The server deserializes the payload without validating it, allowing execution of arbitrary code in the service account context. This flaw is a classic deserialization weakness (CWE‑502) that can compromise confidentiality, integrity, and availability of the affected system. The vulnerability requires no authentication, giving remote attackers full control over the target once the endpoint is reachable.

The flaw affects all installations of Upsonic’s Upsonic product. No specific version range is provided in the advisory, so any deployment running the vulnerable add_tool endpoint contains the vulnerability.

The CVSS score of 9.8 marks this flaw as Critical, confirming the potential for complete system compromise. Although the EPSS score is below 1 %, indicating a low current exploitation probability, the lack of authentication and remote reachability means this vulnerability can be abused once traffic to port 7541 is allowed. The advisory does not place it in the KEV catalog, but the high severity and remote nature warrant urgent attention. Exploitation requires only network access to the service port; no additional credentials or local privileges are needed.