CVE-2026-5444 Orthanc CVE debrief

Who should care

Defenders responsible for Orthanc Server deployments should assess exposure and verify the integrity of image parsing logic. Defenders should prioritize verifying Orthanc Server's exposure to crafted DICOM files and assessing the integrity of image parsing logic to prevent potential buffer overflows and exploitation. Operators of Orthanc Server, platform administrators, and security teams should review the vulnerability details and assess their exposure to

Why it matters

Defenders should prioritize verifying Orthanc Server's exposure to crafted DICOM files and assessing the integrity of image parsing logic to prevent potential buffer overflows and exploitation.

• Verify image parsing logic integrity to prevent potential buffer overflows
• Assess exposure to crafted DICOM files to prevent potential exploitation
• Update to the latest version if vulnerable to prevent potential exploitation

Technical summary

The vulnerability exists in the PAM image parsing logic of Orthanc Server. When processing a crafted PAM image embedded in a DICOM file, image dimensions are multiplied using 32-bit unsigned arithmetic, potentially causing an integer overflow during buffer size calculation. This results in the allocation of a small buffer followed by a much larger write operation during pixel processing. The vulnerability can be triggered by specially chosen values that cause an integer overflow during buffer size calculation, resulting in a heap buffer overflow.

Defensive priority

Defenders should prioritize verifying Orthanc Server's exposure to crafted DICOM files and assessing the integrity of image parsing logic.

Recommended defensive actions

• Verify Orthanc Server's exposure to crafted DICOM files
• Assess the integrity of image parsing logic
• Update to the latest version if vulnerable
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. The vulnerability exists in the PAM image parsing logic of Orthanc Server. When processing a crafted PAM image embedded in a DICOM file, image dimensions are multiplied using 32-bit unsigned arithmetic, potentially causing an integer overflow during buffer size calculation. This results in the allocation of a small buffer followed by a much larger write operation during pixel processing. Defenders should

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.