HOMEVULNERABILITIESCVE-2026-5439
HIGH

CVE-2026-5439

Published: April 9, 2026· Updated: Apr 15, 2026

7.5
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:4.0th

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.

NVD Source

Technical Analysis

CVE-2026-5439 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

orthanc-server1 product
orthanc
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories

ADVISORYhttps://kb.cert.org/vuls/id/536588

All References (3)

→
https://kb.cert.org/vuls/id/536588Third Party Advisory · VDB Entry
→
https://www.machinespirits.de/Not Applicable
→
https://www.orthanc-server.com/Product

Quick Facts

CVE IDCVE-2026-5439
CVSS Score7.5 / 10
SeverityHIGH
CISA KEVNo
EPSS (30d)0.02%
Affected1 vendor
PublishedApr 9, 2026

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-5439 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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