SYSTEM privilege escalation via HIMDS port prebinding
Published Mar 10, 2026 · Updated Mar 10, 2026
Authentication bypass in Microsoft Azure Connected Machine agent before 1.61 allows local users to gain SYSTEM privileges on Windows. The delayed-start HIMDS service leaves HTTP port 40342 available for prebinding, so a user-controlled listener impersonates HIMDS and returns forged metadata and token responses. Low-privileged access and a device restart are required; successful exploitation enables SYSTEM code execution and control of the machine's Azure Arc identity.
Summary
What happened
Authentication bypass in Microsoft Azure Connected Machine agent before 1.61 allows local users to gain SYSTEM privileges on Windows. The delayed-start HIMDS service leaves HTTP port 40342 available for prebinding, so a user-controlled listener impersonates HIMDS and returns forged metadata and token responses. Low-privileged access and a device restart are required; successful exploitation enables SYSTEM code execution and control of the machine's Azure Arc identity.
The record
- CVE
- CVE-2026-26117
- Published
- Mar 10, 2026
- Updated
- Mar 10, 2026
- Vendor
- Microsoft
- Product
- Azure Connected Machine agent
- Classifications
- CWE-288, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 10, 2026CVE publishedPublication date reported by the CVE source.
- Mar 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0.0 <1.61
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cymulate HIMDS port-hijacking walkthroughfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo