Orthanc DICOM Server
Overview
A serious vulnerability has been identified in the Orthanc DICOM Server, affecting versions prior to 1.13.0. This flaw allows an authenticated remote attacker to exploit an integer overflow when the server decodes specially crafted PNG or JPEG images, potentially leading to a crash of the Orthanc process and causing a denial-of-service condition. The issue has been assigned CVE-2026-87020 and has a high severity score of 8.1 according to the CVSS metrics. Users of Orthanc DICOM Server worldwide, particularly in healthcare sectors, are at risk and are strongly urged to update to version 1.13.0 to mitigate the threat. No active exploitation of this vulnerability has been reported so far, but organizations should remain vigilant and take appropriate defensive measures.
Key Takeaways
- Affected Systems: Orthanc DICOM Server versions <1.13.0, Vendor: Orthanc
- Action Required: Users should update to Orthanc DICOM Server version 1.
- Timeline: Disclosed on 2026-09-10
Original Article Summary
View CSAF Summary Successful exploitation of this vulnerability could allow an authenticated remote attacker to write past the end of a heap allocation when Orthanc decodes an attacker-supplied PNG or JPEG image, resulting in a crash of the Orthanc process and a denial-of-service condition. The following versions of Orthanc DICOM Server are affected: Orthanc DICOM Server <1.13.0. (CVE-2026-87020) CVSS Vendor Equipment Vulnerabilities v3 8.1 Orthanc Orthanc DICOM Server Integer Overflow or Wraparound Background Critical Infrastructure Sectors: Healthcare and Public Health Countries/Areas Deployed: Worldwide Company Headquarters Location: Belgium Vulnerabilities Expand All + CVE-2026-87020 An integer overflow in a specified pitch and buffer-size computation leads to a heap out-of-bounds write when Orthanc decodes an attacker-supplied PNG. View CVE Details Affected Products Orthanc DICOM Server Vendor: Orthanc Product Version: Orthanc DICOM Server: <1.13.0. Product Status: known_affected Remediations Mitigation Orthanc recommends users update to v1.13.0. https://orthanc.uclouvain.be/downloads/index.html Relevant CWE: CWE-190 Integer Overflow or Wraparound Metrics CVSS Version Base Score Base Severity Vector String 3.1 8.1 HIGH CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H 4.0 7.2 HIGH CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N Acknowledgments Andrej Tomci reported this vulnerability to CISA. Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. Revision History Initial Release Date: 2026-09-10 Date Revision Summary 2026-09-10 1 Initial Publication Legal Notice and Terms of Use
Impact
Orthanc DICOM Server versions <1.13.0, Vendor: Orthanc
Exploitation Status
No active exploitation has been reported at this time. However, organizations should still apply patches promptly as proof-of-concept code may exist.
Timeline
Disclosed on 2026-09-10
Remediation
Users should update to Orthanc DICOM Server version 1.13.0. Additionally, it is recommended to minimize network exposure for control system devices and use secure remote access methods such as VPNs.
Additional Information
This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.
Related Topics: This incident relates to Phishing, CVE, Exploit, and 3 more.