Microsoft Mitigates Maximum-Severity Azure AI Foundry Flaw

Microsoft has mitigated CVE-2026-85889, a maximum-severity vulnerability in Azure AI Foundry that could have allowed an unauthenticated attacker to elevate privileges over a network. The flaw has a CVSS score of 10.0, and Microsoft said no customer action is required.

Azure AI Foundry, also known as Microsoft Foundry, is Microsoft’s enterprise platform for building, deploying and managing generative AI applications and agents. Microsoft described the defect as missing authentication for a critical function and credited security researcher Rémy Marot for discovering and reporting it.

Cloud service flaw was already mitigated

Microsoft said the Azure AI Foundry issue has been fully mitigated. It also stated that there is no evidence of exploitation in the wild. This remediation model is typical of cloud-service CVEs, where the provider can apply a fix directly rather than requiring customers to deploy software updates.

The disclosure nevertheless places a critical authentication failure in an enterprise AI platform among Microsoft’s most severe recent security issues. For organisations using cloud AI services, provider remediation removes the immediate patching task but does not remove the need to understand which applications, agents and identities rely on the service.

Other high-severity fixes span Microsoft services

Microsoft also addressed CVE-2026-85885, a CVSS 9.9 command injection vulnerability in Microsoft 365 Copilot; CVE-2026-85878, a CVSS 9.9 improper-authorisation flaw in Azure Database for PostgreSQL; and CVE-2026-87701, a CVSS 9.6 improper-neutralisation vulnerability in Azure Cosmos DB. Each could enable an authorised attacker to elevate privileges over a network.

Those cloud vulnerabilities were also fully mitigated by Microsoft and require no customer action. The breadth of the fixes is notable alongside critical Windows weaknesses and patching obligations, which documents critical Windows weaknesses and reinforces the need to distinguish provider-managed cloud remediation from endpoint patching obligations.

Windows fixes require an out-of-band update

Separately, Microsoft released an out-of-band update for Windows 11, version 26H1, to address two local privilege-escalation vulnerabilities. CVE-2026-62721, rated 7.8, affects Windows User-Mode Power Service and could let an authorised attacker gain SYSTEM privileges locally. CVE-2026-85921, rated 8.2, is a double-free vulnerability in Windows Secure Kernel Mode that could allow an authorised attacker to gain Virtual Trust Level 1 privileges locally.

The fixes are included in KB5129194, build 28000.2956, for both arm64-based and x64-based Windows 11 version 26H1 systems. Microsoft’s recent patch activity also included 974 vulnerabilities across its portfolio, while two Windows issues involving ALPC and the Windows Update Stack were reported as actively exploited.

For businesses, the immediate implication is to record Microsoft’s cloud mitigations in risk and change-management processes, verify deployment of KB5129194 where applicable, and keep identity, privilege and endpoint monitoring aligned with the services and Windows versions in use.