CVE-2026-5437 Out-of-Bounds Read in DicomStreamReader
An out-of-bounds read in Orthanc DICOM server allows attackers to potentially read memory contents via malformed metadata, requiring a patch.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-5437?
CVE-2026-5437 is a high-severity 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 `DicomStreamReader` during DICOM meta-header parsing. When processing malformed metadata structures, the parser may read beyond the bounds of the allocated metadata buffer. Although this issue does not typically crash the server or expose data directly to the attacker, it reflects insufficient input validation in the parsing logic.
Weakness: CWE-125
Which versions are affected by CVE-2026-5437?
It affects 1 product.
Products include Orthanc-Server Orthanc.
How do I fix CVE-2026-5437?
Apply the vendor's patch.
Is CVE-2026-5437 being exploited?
There is no known exploitation of CVE-2026-5437 in the wild and no public exploit code.
Other vulnerabilities in Orthanc DICOM Server
- CVE-2026-5442 Heap Buffer Overflow in DICOM Image Decoder via VR UL Dimensions
- CVE-2026-5443 Heap Buffer Overflow in DICOM Image Decoder (Palette Color Decode)
- CVE-2025-0896 Orthanc Server Missing Authentication for Critical Function
- CVE-2026-5445 Out-of-Bounds Read in DicomImageDecoder (DecodeLookupTable)
- CVE-2023-33466 Path traversal in n/a
Sources
Also known as DEBIAN-CVE-2026-5437, GHSA-gqwr-8hwp-hh46, UBUNTU-CVE-2026-5437.