Vulnerability · Published Apr 9, 2026 · Assigned by certcc
CVE-2026-5445Out-of-Bounds Read in DicomImageDecoder (DecodeLookupTable)
Critical 9.1
In plain English
A critical-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 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | orthanc | no fix listed | DEBIAN-CVE-2026-5445 |
| Debian:13 | orthanc | no fix listed | DEBIAN-CVE-2026-5445 |
| Debian:14 | orthanc | 1.12.10+dfsg-4 | DEBIAN-CVE-2026-5445 |
| Ubuntu:22.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5445 |
| Ubuntu:24.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5445 |
| Ubuntu:25.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5445 |
| Ubuntu:26.04:LTS | orthanc | no fix listed | UBUNTU-CVE-2026-5445 |
| Ubuntu:26.10 | orthanc | no fix listed | UBUNTU-CVE-2026-5445 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Orthanc | DICOM Server | 0 – through 1.12.10 |