Microsoft Patches Azure AI Foundry Flaw With Maximum CVSS Score of 10.0

Microsoft has released a fix for a maximum-severity vulnerability in its cloud platform Azure AI Foundry (also known as Microsoft Foundry). This enterprise environment is designed for building, deploying and managing generative AI applications and agents.

What's known about the vulnerability

The flaw has been assigned the identifier CVE-2026-85889 and a CVSS score of 10.0 — the highest possible. According to an advisory published on Thursday, the issue stems from missing authentication for a critical function: this allowed an unauthenticated attacker to elevate their privileges over the network. In other words, the attack required neither credentials nor physical access.

The vulnerability was discovered and reported by security researcher Rémy Marot. The company found no signs of the flaw being exploited in real-world attacks. As is usually the case with cloud vulnerabilities, Microsoft resolved the issue entirely on its own end, so no action is required from users.

Other critical fixes

At the same time, Microsoft closed several other serious vulnerabilities in its cloud services:

• CVE-2026-85885 (CVSS 9.9) — a command injection in Microsoft 365 Copilot that lets an authenticated attacker elevate privileges over the network;
• CVE-2026-85878 (CVSS 9.9) — improper authorization in Azure Database for PostgreSQL;
• CVE-2026-87701 (CVSS 9.6) — a vulnerability in Azure Cosmos DB.

Separately, updates were released for two local vulnerabilities in Windows 11 version 26H1 — they ship in the out-of-band cumulative package KB5129194. These are CVE-2026-62721 (CVSS 7.8) in the Windows User-Mode Power Service, granting SYSTEM privileges, and CVE-2026-85921 (CVSS 8.2) — a double-free in Secure Kernel Mode with elevation to the VTL1 trust level.

Against the backdrop of a record Patch Tuesday

The current patches came just days after Microsoft closed a record 974 vulnerabilities as part of its scheduled update. Two of them — in the Windows ALPC and Windows Update Stack subsystems — are already under active exploitation. According to Proofpoint and Volexity, the ALPC flaw was combined with two Google Chrome vulnerabilities into an exploit kit dubbed BlueMoon, which several cyber-espionage groups have adopted to deliver malicious payloads.

Source: The Hacker News