Heap-based buffer overflow in Orthanc - CVE-2026-5442
Published: April 9, 2026
Vulnerability identifier: #VU125673
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-5442
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Orthanc
Affected software:
Orthanc
Orthanc
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to heap-based buffer overflow in the DICOM image decoder when decoding images with dimension fields encoded as VR Unsigned Long values. A remote attacker can supply a crafted DICOM file with extremely large dimensions to execute arbitrary code.
The issue is triggered by an integer overflow during frame size calculation.
How to mitigate CVE-2026-5442
Install security update from vendor's website.