# CVE-2026-44034: Heap out-of-bounds read in DCMTK RLE decodeFrame()

> An attacker can read adjacent heap memory or crash the application by providing a crafted DICOM file to the DCMTK library.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **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:** No
- **Published:** 8 Oct 2026
- **Updated:** 8 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-44034, GHSA-mmr5-x4mp-rpf4, UBUNTU-CVE-2026-44034

## What is CVE-2026-44034?

CVE-2026-44034 is a medium-severity memory corruption vulnerability in OFFIS DCMTK, published on 8 Oct 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

A heap-based out-of-bounds read in DcmRLECodecDecoder::decodeFrame() in dcmdata/libsrc/dcrleccd.cc of OFFIS DCMTK 3.7.0 allows an attacker to read up to 63 bytes of adjacent heap memory, or cause a crash, via a crafted RLE Lossless DICOM file whose pixel data fragment is shorter than the 64-byte RLE header. The function copies 64 bytes without checking the fragment length, a check that the sibling function decode() already performs. Applications that decode RLE images frame by frame (for example, through DcmPixelData::getUncompressedFrame()) are affected. The dcmdrle command-line tool uses decode() and is not affected. The issue is fixed in commit 45469f3c30037e9c7159290e4bb74cd7b3b9ef1d.

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

## Which versions are affected by CVE-2026-44034?


## How do I fix CVE-2026-44034?

No fix has been published for CVE-2026-44034 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-44034 being exploited?

There is no known exploitation of CVE-2026-44034 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44034 and fix it if it is affected.

What it is: CVE-2026-44034 is a medium-severity memory corruption vulnerability in OFFIS DCMTK, published on 8 Oct 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-2026-44034 in the wild and no public exploit code.

Affected product: OFFIS DCMTK. 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-2026-44034/ (Markdown: https://insights.sbomify.com/CVE-2026-44034/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44034
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44034
- OSV: https://osv.dev/vulnerability/CVE-2026-44034

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-44034/
Summaries are generated and may contain mistakes; the official description above is the record.