Orthanc DICOM Server up to 1.12.10 ZIP Archive size allocation of resources

Summaryinfo

A vulnerability described as problematic has been identified in Orthanc DICOM Server up to 1.12.10. Impacted is an unknown function of the component ZIP Archive Handler. The manipulation of the argument size results in allocation of resources. This vulnerability is reported as CVE-2026-5439. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Orthanc DICOM Server up to 1.12.10. Affected is an unknown code block of the component ZIP Archive Handler. The manipulation of the argument size with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. CVE summarizes:

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.

This vulnerability is traded as CVE-2026-5439 since 04/02/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-20916). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• Orthanc

Name

• DICOM Server

Version

• 1.12.0
• 1.12.1
• 1.12.2
• 1.12.3
• 1.12.4
• 1.12.5
• 1.12.6
• 1.12.7
• 1.12.8
• 1.12.9
• 1.12.10

CPE 2.3info

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CPE 2.2info

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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