# CVE-2026-5445: Out-of-Bounds Read in DicomImageDecoder (DecodeLookupTable)

> Attackers can craft DICOM images to trigger an out-of-bounds read, exposing heap memory contents in the decoded output.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Apr 2026
- **Updated:** 14 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-5445, GHSA-g69c-6pfv-54p9, UBUNTU-CVE-2026-5445

## What is CVE-2026-5445?

CVE-2026-5445 is a critical vulnerability in Orthanc DICOM Server, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-5445?

It affects 1 product.


Products: Orthanc-Server Orthanc.

## How do I fix CVE-2026-5445?

Apply the vendor's patch.

## Is CVE-2026-5445 being exploited?

There is no known exploitation of CVE-2026-5445 in the wild and no public exploit code.

## Other vulnerabilities in Orthanc DICOM Server

- [CVE-2026-5442](https://insights.sbomify.com/CVE-2026-5442/): Heap Buffer Overflow in DICOM Image Decoder via VR UL Dimensions (critical 9.8)
- [CVE-2026-5443](https://insights.sbomify.com/CVE-2026-5443/): Heap Buffer Overflow in DICOM Image Decoder (Palette Color Decode) (critical 9.8)
- [CVE-2025-0896](https://insights.sbomify.com/CVE-2025-0896/): Orthanc Server Missing Authentication for Critical Function (critical 9.2)
- [CVE-2023-33466](https://insights.sbomify.com/CVE-2023-33466/): Path traversal in n/a (high 8.8)
- [CVE-2026-5437](https://insights.sbomify.com/CVE-2026-5437/): Out-of-Bounds Read in DicomStreamReader (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5445 and fix it if it is affected.

What it is: CVE-2026-5445 is a critical vulnerability in Orthanc DICOM Server, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5445 in the wild and no public exploit code.

Affected product: Orthanc DICOM Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5445/ (Markdown: https://insights.sbomify.com/CVE-2026-5445/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5445
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5445
- OSV: https://osv.dev/vulnerability/CVE-2026-5445

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5445/
Summaries are generated and may contain mistakes; the official description above is the record.