CVE-2026-5439
Memory Exhaustion via Forged ZIP Metadata
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Memory Exhaustion via Forged ZIP Metadata
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.
- Record
CVE-2026-5439- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
EUVDEUVD-2026-20916
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.
- Record
EUVD-2026-20916- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6cmv-pvcc-pf5h
A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically...
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.
- Record
GHSA-6cmv-pvcc-pf5h- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-5439- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVDEBIAN-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.
- Record
DEBIAN-CVE-2026-5439- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2026-5439- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
orthancDebian:12 |
All versions, plus listed versions 1.10.1+dfsg-21.10.1+dfsg-2+deb12u11.12.1+dfsg-11.12.1+dfsg-21.12.1+dfsg-3 Show 31 moreShow less1.12.1+dfsg-41.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.10+dfsg-41.12.10+dfsg-51.12.11+dfsg-11.12.11+dfsg-21.12.11+dfsg-31.12.11+dfsg-41.12.11+dfsg-51.12.11+dfsg-61.12.11+dfsg-71.12.11+dfsg-81.12.2+dfsg-11.12.3+dfsg-11.12.3+dfsg-21.12.4+dfsg-11.12.4+dfsg-21.12.4+dfsg-31.12.4+dfsg-41.12.5+dfsg-11.12.5+dfsg-21.12.6+dfsg-11.12.7+dfsg-11.12.7+dfsg-21.12.7+dfsg-31.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-21.13.0+dfsg-1 |
None known |
orthancDebian:13 |
All versions, plus listed versions 1.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.10+dfsg-41.12.10+dfsg-5 Show 12 moreShow less1.12.11+dfsg-11.12.11+dfsg-21.12.11+dfsg-31.12.11+dfsg-41.12.11+dfsg-51.12.11+dfsg-61.12.11+dfsg-71.12.11+dfsg-81.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-21.13.0+dfsg-1 |
None known |
orthancDebian:14 |
before 1.12.10+dfsg-4, plus listed versions 1.12.10+dfsg-11.12.10+dfsg-21.12.10+dfsg-31.12.7+dfsg-41.12.9+dfsg-11.12.9+dfsg-2 |
1.12.10+dfsg-4 |
orthancUbuntu:16.04:LTS |
All versions, plus listed versions 0.9.4+dfsg-10.9.4+dfsg-20.9.5+dfsg-11.0.0+dfsg-11.0.0+dfsg-1build1 |
None known |
orthancUbuntu:18.04:LTS |
All versions, plus listed versions 1.3.0+dfsg-1build11.3.0+dfsg-1build21.3.1+dfsg-11.3.1+dfsg-1build11.3.1+dfsg-1build2 |
None known |
orthancUbuntu:20.04:LTS |
All versions, plus listed versions 1.5.7+dfsg-21.5.8+dfsg-21.5.8+dfsg-2ubuntu21.5.8+dfsg-2ubuntu31.5.8+dfsg-2ubuntu41.5.8+dfsg-2ubuntu51.5.8+dfsg-2ubuntu6 |
None known |
orthancUbuntu:22.04:LTS |
All versions, plus listed versions 1.9.2+really1.9.1+dfsg-11.9.7+dfsg-3ubuntu11.9.7+dfsg-3ubuntu21.9.7+dfsg-41.9.7+dfsg-51.9.7+dfsg-61.10.0+dfsg-1 |
None known |
orthancUbuntu:24.04:LTS |
All versions, plus listed versions 1.12.1+dfsg-31.12.1+dfsg-41.12.1+dfsg-4build11.12.2+dfsg-11.12.2+dfsg-1build31.12.2+dfsg-1build4 |
None known |
orthancUbuntu:25.10 |
All versions, plus listed versions 1.12.6+dfsg-11.12.7+dfsg-41.12.7+dfsg-4build2 |
None known |
orthancUbuntu:26.10 |
All versions, plus listed versions 1.12.10+dfsg-21.12.11+dfsg-81.12.11+dfsg-8build1 |
None known |
orthancUbuntu:26.04:LTS |
All versions, plus listed versions 1.12.7+dfsg-4build21.12.9+dfsg-21.12.10+dfsg-11.12.10+dfsg-1build11.12.10+dfsg-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5439 is a high vulnerability (CVSS 7.5) in Orthanc-server Orthanc, published April 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.43%, the 37th percentile. Fixed in orthanc 1.12.10+dfsg-4.