Critical Vulnerabilities in Orthanc DICOM Server Threaten Healthcare Systems

Multiple critical vulnerabilities have been discovered in the Orthanc DICOM server, affecting all versions up to 1.12.10. These vulnerabilities, including CVE-2026-5442, CVE-2026-5438, and CVE-2026-5440, allow attackers to exploit unsafe arithmetic operations and insufficient validation of DICOM files, leading to server crashes, memory exhaustion, and potential remote code execution. The flaws can be triggered by submitting specially crafted DICOM files or HTTP requests, posing significant risks to healthcare systems that rely on Orthanc for medical imaging. Users are strongly advised to upgrade to version 1.12.11 or later to mitigate these threats. The vulnerabilities were publicly disclosed on April 9, 2026, and have been categorized as critical due to their potential impact on patient privacy and operational continuity.

Key Points: • Critical vulnerabilities in Orthanc DICOM server affect all versions up to 1.12.10. • Exploitation can lead to server crashes, memory exhaustion, and remote code execution. • Immediate upgrade to version 1.12.11 or later is required to mitigate risks.