What is CVE-2026-85887?

CVE-2026-85887 is a high-severity vulnerability in Microsoft 365 Copilot, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 7.7/10. Published 2026-09-18.

How severe is CVE-2026-85887?

High severity. CVSS v3 base score is 7.7 out of 10.

Vulnerability in Microsoft 365 Copilot

CVE-2026-85887

Incorrect permission assignment for critical resource in M365 Copilot allows an authorized attacker to disclose information over a network.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

Affected products

Microsoft 365 Copilot

Weakness classification (CWE)

CWE-732 — Incorrect Permission Assignment for Critical Resource

References

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

Frequently asked questions

What is CVE-2026-85887?: CVE-2026-85887 is a high-severity vulnerability in Microsoft 365 Copilot, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 7.7/10. Published 2026-09-18.
How severe is CVE-2026-85887?: High severity. CVSS v3 base score is 7.7 out of 10.