What is CVE-2026-41090?

CVE-2026-41090 is a critical-severity vulnerability in Microsoft 365_copilot, classified under Command Injection. CVSS score: 9.3/10. Published 2026-05-22.

How severe is CVE-2026-41090?

Critical severity. CVSS v3 base score is 9.3 out of 10.

RCE in Microsoft 365_copilot

CVE-2026-41090

Improper neutralization of special elements used in a command ('command injection') in Microsoft Copilot allows an unauthorized attacker to perform tampering over a network.

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.001 (16.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.

Affected products

Microsoft 365_copilot
Microsoft 365 Copilot For Ios

Weakness classification (CWE)

CWE-77 — Command Injection

References

secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-41090?: CVE-2026-41090 is a critical-severity vulnerability in Microsoft 365_copilot, classified under Command Injection. CVSS score: 9.3/10. Published 2026-05-22.
How severe is CVE-2026-41090?: Critical severity. CVSS v3 base score is 9.3 out of 10.