PatchSiren cyber security CVE debrief

CVE-2026-40412 Microsoft CVE debrief

A critical unauthenticated remote code execution vulnerability exists in Azure Orbital Spatio due to unrestricted file upload of dangerous types (CWE-434). The vulnerability carries a CVSS 3.1 score of 10.0 (Critical), indicating maximum severity with network attack vector, low attack complexity, no privileges required, no user interaction, and scope change affecting confidentiality, integrity, and availability. The vulnerability was published to the CVE Program on May 22, 2026, and last modified on May 26, 2026. As of the modified date, the NVD entry status remains 'Undergoing Analysis.' Microsoft has acknowledged this vulnerability through their Security Response Center. No known exploitation in ransomware campaigns has been documented, and the vulnerability has not been added to CISA's Known Exploited Vulnerabilities catalog.

Vendor: Microsoft
Product: Azure Orbital Spatio
CVSS: CRITICAL 10
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-05-22
Original CVE updated: 2026-05-27
Advisory published: 2026-05-22
Advisory updated: 2026-05-27

Who should care

Organizations operating Azure Orbital Spatio services, cloud security teams managing Microsoft Azure deployments, and security operations centers monitoring for critical unauthenticated RCE vulnerabilities in cloud infrastructure components.

Technical summary

The vulnerability stems from improper restriction of file uploads with dangerous types (CWE-434) in Azure Orbital Spatio. An unauthenticated attacker can exploit this weakness over a network to achieve arbitrary code execution. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H) indicates the vulnerability is exploitable from the network without authentication, can affect resources beyond the vulnerable component (scope change), and results in complete compromise of confidentiality, integrity, and availability.

Defensive priority

critical

Recommended defensive actions

Apply security updates from Microsoft MSRC as soon as available
Review Azure Orbital Spatio deployments for unauthorized file upload functionality
Implement network segmentation to restrict access to Azure Orbital Spatio management interfaces
Enable comprehensive logging for file upload operations in affected services
Monitor for anomalous file upload patterns and unexpected process execution
Validate file type restrictions and content inspection controls for all upload endpoints

Evidence notes

Vulnerability description sourced from official CVE record and NVD entry. CVSS vector confirms network-accessible unauthenticated RCE with scope change. Microsoft MSRC reference confirms vendor acknowledgment. Vendor attribution to Microsoft derived from reference domain candidate with low confidence flag; 'Unknown Vendor' designation in source requires review.

Official resources

2026-05-22T23:16:51.363Z