Out-of-bounds Read in Orthanc Dicom Server
CVE-2026-5445
An out-of-bounds read vulnerability exists in the `DecodeLookupTable` function within `DicomImageDecoder.cpp`. The lookup-table decoding logic used for `PALETTE COLOR` images does not validate pixel indices against the lookup table size. Crafted images containing indices larger than the palette size cause the decoder to read beyond allocated lookup table memory and expose heap contents in the output image.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.007 · change: -0.001
Affected products
- Orthanc Dicom Server — versions 0
- Orthanc-Server Orthanc
Weakness classification (CWE)
References
- www.orthanc-server.com/ (Product)
- www.machinespirits.de/ (Not Applicable)
- kb.cert.org/vuls/id/536588 (VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-5445?
- CVE-2026-5445 is a critical-severity vulnerability in Orthanc Dicom Server, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-04-09.
- How severe is CVE-2026-5445?
- Critical severity. CVSS v3 base score is 9.1 out of 10.