Orthanc DICOM Server up to 1.12.10 Gzip Content-Encoding allocation of resources

Summaryinfo

A vulnerability labeled as problematic has been found in Orthanc DICOM Server up to 1.12.10. Affected by this vulnerability is an unknown functionality of the component Gzip Handler. Such manipulation of the argument Content-Encoding leads to allocation of resources. This vulnerability is documented as CVE-2026-5438. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Orthanc DICOM Server up to 1.12.10 and classified as problematic. Affected by this issue is an unknown part of the component Gzip Handler. The manipulation of the argument Content-Encoding with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to 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. Impacted is availability. CVE summarizes:

A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content-Encoding: gzip`. The server does not enforce limits on decompressed size and allocates memory based on attacker-controlled compression metadata. A specially crafted gzip payload can trigger excessive memory allocation and exhaust system memory.

This vulnerability is handled as CVE-2026-5438 since 04/02/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

The vulnerability scanner Nessus provides a plugin with the ID 305830 (Linux Distros Unpatched Vulnerability : CVE-2026-5438), which helps to determine the existence of the flaw in a target environment.

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 databases at Tenable (305830) and EUVD (EUVD-2026-20914). 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

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

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

Discussion