The vulnerability resides in the CFE_MSG_GetSize function within the to_lab_passthru_encode.c source of the CCSDS Packet Header Handler component in NASA's Core Flight System. An attacker can craft malformed input over the local network to trigger a heap‑based buffer overflow. The overflow can corrupt adjacent memory, potentially causing a crash or allowing arbitrary code execution on the host. This weakness aligns with CWE‑119 and CWE‑122 and represents a classic memory corruption flaw.

Affected systems include NASA’s cFS software up to and including version 7.0.0. The vulnerability manifests in the to_lab_passthru_encode component, which is part of the overall cFS application set used in many satellite flight software scenarios. Users running non‑patched versions of cFS in any environment that permits local network interaction are subject to this risk.

The CVSS score of 5.3 indicates a moderate severity level, and the EPSS rating is not available, suggesting no publicly documented exploitation attempts yet. KEV listing is absent, so there is no confirmation of widespread exploitation. The required local network access limits the attack surface to internal or compromised nodes; however, once inside, the attacker could destabilize the flight software or potentially take control if the overflow is successfully leveraged. As such, the risk remains moderate but requires timely mitigation, especially for mission‑critical deployments.