What is CVE-2026-5439?

CVE-2026-5439 is a high-severity vulnerability in Orthanc Dicom Server, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-04-09.

How severe is CVE-2026-5439?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Orthanc Dicom Server

CVE-2026-5439

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.

EPSS: 0.004 (35.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Orthanc Dicom Server — versions 0
Orthanc-server Orthanc

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

cret@cert.org (Product)
cret@cert.org (Not Applicable)
cret@cert.org (VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2026-5439?: CVE-2026-5439 is a high-severity vulnerability in Orthanc Dicom Server, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-04-09.
How severe is CVE-2026-5439?: High severity. CVSS v3 base score is 7.5 out of 10.