Orthanc Server is a lightweight, open-source Picture Archiving and Communication System (PACS) platform used in medical imaging environments, with a focused product footprint centered on the core Orthanc application and the Osimis Web Viewer component. The vendor's vulnerability disclosures, while modest in volume, reflect its specialized role in healthcare IT infrastructure where the attack surface and deployment context of a medical imaging server differ from general enterprise systems. Current severity, exploitation activity, and exposure counts are shown alongside this summary.
The number and severity of CVEs published that impact products developed by Orthanc Server over time
Signals from CVEs in this vendor scope (14 CVEs).
14 CVEs · Highest risk first
| CVE | Published | CVSS | Risk | KEV | Exploit |
|---|---|---|---|---|---|
CVE-2026-5443CRITICAL A heap buffer overflow vulnerability exists during the decoding of `PALETTE COLOR` DICOM images. Pixel length validation uses 32-bit multiplication for width and height calculation | Apr 9, 2026 | 9.8 | 31 | NO | NO |
CVE-2026-5442CRITICAL A heap buffer overflow vulnerability exists in the DICOM image decoder. Dimension fields are encoded using Value Representation (VR) Unsigned Long (UL), instead of the expected VR | Apr 9, 2026 | 9.8 | 31 | NO | NO |
CVE-2026-5445CRITICAL An out-of-bounds read vulnerability exists in the `DecodeLookupTable` function within `DicomImageDecoder.cpp`. The lookup-table decoding logic used for `PALETTE COLOR` images does | Apr 9, 2026 | 9.1 | 30 | NO | NO |
CVE-2023-33466HIGH Orthanc before 1.12.0 allows authenticated users with access to the Orthanc API to overwrite arbitrary files on the file system, and in specific deployment scenarios allows the att | Jun 29, 2023 | 8.8 | 30 | NO | NO |
CVE-2025-0896CRITICAL Orthanc server prior to version 1.5.8 does not enable basic authentication by default when remote access is enabled. This could result in unauthorized access by an attacker. | Feb 13, 2025 | 9.8 | 28 | NO | NO |
CVE-2026-5437HIGH An out-of-bounds read vulnerability exists in `DicomStreamReader` during DICOM meta-header parsing. When processing malformed metadata structures, the parser may read beyond the bo | Apr 9, 2026 | 7.5 | 26 | NO | NO |
CVE-2026-5440HIGH A memory exhaustion vulnerability exists in the HTTP server due to unbounded use of the `Content-Length` header. The server allocates memory directly based on the attacker supplie | Apr 9, 2026 | 7.5 | 25 | NO | NO |
CVE-2026-5439HIGH A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives uploaded to certain endpoints and trusts metadata fields describing | Apr 9, 2026 | 7.5 | 25 | NO | NO |
CVE-2026-5438HIGH A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content-Encoding: gzip`. The server does not enforce limits on decompressed size and alloca | Apr 9, 2026 | 7.5 | 25 | NO | NO |
CVE-2026-5444HIGH A heap buffer overflow vulnerability exists in the PAM image parsing logic. When Orthanc processes a crafted PAM image embedded in a DICOM file, image dimensions are multiplied usi | Apr 9, 2026 | 7.1 | 24 | NO | NO |
Signals from CVEs in this vendor scope (14 CVEs).
An overview of all social media posts that mention a CVE ID that affects a product developed by Orthanc Server.
Media articles that mention a CVE ID that affects a product developed by Orthanc Server — matched by CVE ID, not by vendor name.