# CVE-2026-5441: Out-of-Bounds Read in DicomImageDecoder (PMSCT_RLE1 Decompression)

> Attackers can leak heap data via crafted DICOM images due to an out-of-bounds read in the Philips compression decoder, affecting Orthanc server deployments.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Apr 2026
- **Updated:** 14 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-5441, GHSA-5jvx-5q86-rxx3, UBUNTU-CVE-2026-5441

## What is CVE-2026-5441?

CVE-2026-5441 is a high-severity vulnerability in Orthanc DICOM Server, published on 9 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

An out-of-bounds read vulnerability exists in the `DecodePsmctRle1` function of `DicomImageDecoder.cpp`. The `PMSCT_RLE1` decompression routine, which decodes the proprietary Philips Compression format, does not properly validate escape markers placed near the end of the compressed data stream. A crafted sequence at the end of the buffer can cause the decoder to read beyond the allocated memory region and leak heap data into the rendered image output.

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

## Which versions are affected by CVE-2026-5441?

It affects 1 product.


Products: Orthanc-Server Orthanc.

## How do I fix CVE-2026-5441?

Apply the vendor's patch.

## Is CVE-2026-5441 being exploited?

There is no known exploitation of CVE-2026-5441 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-2026-5445](https://insights.sbomify.com/CVE-2026-5445/): Out-of-Bounds Read in DicomImageDecoder (DecodeLookupTable) (critical 9.1)
- [CVE-2023-33466](https://insights.sbomify.com/CVE-2023-33466/): Path traversal in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5441 and fix it if it is affected.

What it is: CVE-2026-5441 is a high-severity vulnerability in Orthanc DICOM Server, published on 9 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-5441 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-2026-5441/ (Markdown: https://insights.sbomify.com/CVE-2026-5441/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5441
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5441
- OSV: https://osv.dev/vulnerability/CVE-2026-5441

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5441/
Summaries are generated and may contain mistakes; the official description above is the record.