A stack-based buffer overflow exists in the Orthanc DICOM Server (version 1.12.11 or earlier) within the DCMTK Parser component. The flaw resides in the DcmItem::read method of FromDcmtkBridge.cpp, enabling an attacker who can control the input data to overflow a stack buffer. The result can be arbitrary code execution on the server, as the vulnerability is triggered by passing a specially crafted DICOM file. The flaw is classified under CWE‑119 and CWE‑121, indicating a buffer overflow and stack-based buffer overflow weakness.

Orthanc DICOM Server up to version 1.12.11. The vulnerability affects all platforms where the affected build is deployed, as it relies on the processing of DICOM data files by the DCMTK Parser. No specific operating system is limited; any local user able to submit a DICOM file to the server is able to exercise the flaw.

The CVSS score of 4.8 reflects moderate severity, and no EPSS score is available. The vulnerability is listed as not being in the CISA KEV catalog. Attacking locally is required, but a public exploit has been released, indicating that an attacker with local access to the service can insert malicious DICOM data. Because the flaw leads to a stack overflow, an exploitation attempt has a high likelihood of succeeding for a malicious local attacker, potentially resulting in local code execution.