# CVE-2026-5439: orthanc: A memory exhaustion vulnerability exists in ZIP archive processing

CVE-2026-5439 is fixed in orthanc on 1 platform by DEBIAN-CVE-2026-5439 (version 1.12.10+dfsg-4), released April 9, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-5439
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0043
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 9, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | orthanc Debian 14 | 1.12.10+dfsg-4 | [DEBIAN-CVE-2026-5439](https://patchblox.com/security/data/fix/linux/debian-cve-2026-5439.md) | Apr 9, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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