Microsoft 365 Copilot For Android CVE-2026-26133

M365 Copilot must be accessible to attacker; user must interact with crafted prompt (UI:R); no authentication required; default or standard Copilot configurations vulnerable to command injection payloads.

Despite the high CVSS score of 7.1, the real-world risk appears moderate. The CVSS vector (AV:N/AC:L/PR:N/UI:R) indicates remote exploitation is possible without authentication but requires user interaction. Key risk factors: No EPSS score suggests low exploitation probability, not listed in CISA KEV indicating no known active exploitation, no public POC available, and patches are already released. The 'High' confidentiality impact could expose sensitive business data through Copilot, but the user interaction requirement and lack of exploitation evidence reduce immediate risk. This is likely a high-CVSS-but-moderate-real-risk issue that should be patched during normal maintenance windows rather than emergency response.

An attacker could craft malicious content (document, email, or webpage) containing specially formatted AI command injection payloads. When a user interacts with this content and uses Copilot features, the malicious prompts could manipulate the AI to disclose information it shouldn't access, potentially revealing sensitive business data, personal information, or internal documents indexed by Copilot. The attack requires the victim to actively engage with Copilot while viewing the malicious content, limiting automation potential. No public POC exists, suggesting the technical details remain closely held.