Executive brief
Microsoft Copilot Studio is a tool for building and managing AI-powered assistants. A vulnerability in its cryptographic signature verification allows an attacker on the network to bypass authentication and gain unauthorized access with elevated privileges, potentially compromising sensitive data and operations.
Technical details
The vulnerability is a cryptographic signature verification bypass in Copilot Studio that fails to properly validate digitally signed messages or tokens. This allows an attacker on the network to forge or bypass signature checks without authentication, escalating privileges to perform unauthorized actions. The network-accessible nature of the vulnerability means no local access is required. The improper verification enables privilege escalation attacks that could lead to full system compromise or access to protected resources. Patches are expected to be available from Microsoft through their standard security update process.
Affected products
- Microsoft Copilot Studio
Timeline
- 2026-09-03: disclosed