Heap-based buffer overflow in Orthanc - CVE-2026-5443
Published: April 9, 2026
Vulnerability identifier: #VU125674
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-2026-5443
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 PALETTE COLOR image decoding when validating pixel length using 32-bit multiplication for width and height calculations. A remote attacker can supply a crafted PALETTE COLOR DICOM image to execute arbitrary code.
The issue is triggered when integer overflow causes the validation check to incorrectly succeed.
How to mitigate CVE-2026-5443
Install security update from vendor's website.