CVE-2026-5439
High
Description
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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductOrthanc
PublishedApr 9, 2026
First seenApr 9, 2026
Weakness typeCWE-770Allocation of resources without limits
How to fix
Update
- orthanc-server orthanc1.12.11 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| orthanc-server orthanc | v < 1.12.11 | 1.12.11 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.