What’s Vulnerable › Vulnerabilities
CVE-2026-5439: Memory Exhaustion via Forged ZIP Metadata
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-09 · updated 2026-10-26
- Weakness: CWE-770
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.
Affected products
- orthanc-server orthanc: before 1.12.11 — fixed in 1.12.11
How to fix
Upgrade to a fixed version: orthanc-server orthanc 1.12.11. Check the vendor advisory for mitigations.
References
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