CVE-2026-5443: Orthanc-Server Orthanc

Critical severity, CVSS 9.8. EPSS: 0.9% chance of exploitation in the next 30 days.

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 calculations. If these values overflow, the validation check incorrectly succeeds, allowing the decoder to read and write to memory beyond allocated buffers.

Affected products

• Orthanc-Server Orthanc: before 1.12.11 (fixed in 1.12.11)

Published 2026-04-09. Last modified 2026-06-17.