Critical severity · published Apr 9, 2026
CVE-2026-5442
Heap Buffer Overflow in DICOM Image Decoder via VR UL Dimensions
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
A heap buffer overflow vulnerability exists in the DICOM image decoder. Dimension fields are encoded using Value Representation (VR) Unsigned Long (UL), instead of the expected VR Unsigned Short (US), which allows extremely large dimensions to be processed. This causes an integer overflow during frame size calculation and results in out-of-bounds memory access during image decoding.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DS
DICOM Server · Orthanc
through 1.12.10 · source: vendor
OR
Orthanc · Orthanc-server
before 1.12.11 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5442
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5442
Third Party Advisory
https://kb.cert.org/vuls/id/536588
Not Applicable
https://www.machinespirits.de/
Product
https://www.orthanc-server.com/
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