CVE-2026-5439: high-severity vulnerability in Orthanc DICOM Server
Memory Exhaustion via Forged ZIP Metadata
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.4%
A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives uploaded to certain endpoints and trusts metadata fields describing the uncompressed size of archived files. An attacker can craft a small ZIP archive containing a forged size value, causing the server to allocate extremely large buffers during extraction.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Orthanc · DICOM ServerRelated CVEs — Orthanc DICOM Server
In the same product, most dangerous first.
CVE-2026-5445CRITICALOut-of-Bounds Read in DicomImageDecoder (DecodeLookupTable)EPSS 0.7%CVE-2026-5437HIGHOut-of-Bounds Read in DicomStreamReaderEPSS 0.7%CVE-2026-5442CRITICALHeap Buffer Overflow in DICOM Image Decoder via VR UL DimensionsEPSS 0.6%CVE-2026-5440HIGHMemory Exhaustion via Unbounded Content-LengthEPSS 0.6%CVE-2026-5443CRITICALHeap Buffer Overflow in DICOM Image Decoder (Palette Color Decode)EPSS 0.6%CVE-2026-87020HIGHOrthanc DICOM Server Integer Overflow or WraparoundEPSS 0.6%