CVE-2026-5439: A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives…
CVE-2026-5439 · Severity: high · CVSS 7.5 · Published 2026-04-09
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.
No. Junglewise Threat Intelligence has no report of CVE-2026-5439 being exploited in the wild.
How severe is CVE-2026-5439?
High severity, with a CVSS score of 7.5, published 9 April 2026.
Which products and versions are affected?
Orthanc-Server Orthanc. The advisory does not name versions.
Is there a fix for CVE-2026-5439?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-5439?
Check whether you run Orthanc-Server Orthanc. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.