Vulnerability · Published Apr 9, 2026 · Assigned by certcc
CVE-2026-5439Memory Exhaustion via Forged ZIP Metadata
High 7.5
In plain English
A high-severity security flaw in DICOM Server from Orthanc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.4%top 62.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | orthanc | no fix listed | DEBIAN-CVE-2026-5439 |
| Debian:13 | orthanc | no fix listed | DEBIAN-CVE-2026-5439 |
| Debian:14 | orthanc | 1.12.10+dfsg-4 | DEBIAN-CVE-2026-5439 |
| Ubuntu:22.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5439 |
| Ubuntu:24.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5439 |
| Ubuntu:25.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5439 |
| Ubuntu:26.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5439 |
| Ubuntu:26.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5439 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Orthanc | DICOM Server | 0 – through 1.12.10 |