OrthancApplication · Orthanc Server

CVE-2026-5437

HIGH · 7.5 CVSS v3.1 Published 2026-04-09
Fix available
A fix is available. Upgrade to 1.12.11 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

An out-of-bounds read vulnerability exists in DicomStreamReader's DICOM meta-header parsing logic. When processing malformed metadata structures, the parser reads beyond the allocated metadata buffer boundaries due to insufficient input validation. This memory safety issue could potentially allow disclosure of sensitive memory contents or cause undefined behavior.

MitigationImplement proper bounds checking in the DicomStreamReader meta-header parsing code to validate metadata structure sizes against allocated buffer space before reading. Update to a patched version if available, or add input validation routines to reject malformed DICOM files.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OrthancApplication
Affected:< 1.12.11

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Orthanc Server version
    Run 'Orthanc --version' or check the software's about/version information to determine the installed version number
    Affected if The installed version is lower than 1.12.11 (e.g., 1.12.10, 1.12.0, earlier releases)
  2. Confirm DICOM ingestion is enabled
    Review Orthanc configuration files (orthanc.json) for enabled modalities and DICOM storage paths, or check if the application is actively receiving or processing DICOM files
    Affected if Orthanc is configured to accept and parse incoming DICOM studies or is actively processing DICOM files
  3. Verify DicomStreamReader is in use
    Check Orthanc logs for DICOM parsing activity, or monitor network ports (typically 4242 for DICOM) for incoming connections
    Affected if The server is actively accepting DICOM connections or parsing DICOM metadata from incoming files
  4. Inspect DICOM processing behavior
    Review Orthanc storage directory for recent DICOM files that have been processed, or check application logs for DICOM meta-header parsing operations
    Affected if Orthanc is processing DICOM files and the DicomStreamReader component handles the meta-header parsing

You are affected if Orthanc Server version is below 1.12.11 and the server processes DICOM files containing meta-header data through the DicomStreamReader component.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.12.11 or later
Fixed in 1.12.11
Interim mitigation

Implement proper bounds checking in the DicomStreamReader meta-header parsing code to validate metadata structure sizes against allocated buffer space before reading. Update to a patched version if available, or add input validation routines to reject malformed DICOM files.

Recommended fix High confidence

1.12.11

  1. Identify the current Orthanc version in use
  2. Plan maintenance window for the upgrade
  3. Download Orthanc version 1.12.11 or later from the official source (www.orthanc-server.com)
  4. Backup the current Orthanc configuration and any persistent data
  5. Stop the Orthanc service
  6. Install version 1.12.11
  7. Verify the installation was successful
  8. Restart the Orthanc service

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Orthanc Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-5437 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data