MSRC-CVE-2026-59118 — Copilot Cowork Elevation of Privilege Vulnerability

Summary

Impact: Elevation of Privilege. Microsoft rating: Critical. Not known to be exploited. Customer action: Not required.

Details

Why are there no links to an update or instructions with steps that must be taken to protect from this vulnerability?
This vulnerability has already been fully mitigated by Microsoft. There is no action for users of this service to take. The purpose of this CVE is to provide further transparency.
Please see Toward greater transparency: Unveiling Cloud Service CVEs for more information.

Vulnerabilities 1

Critical 9.3

CVE-2026-59118

Copilot Cowork Elevation of Privilege Vulnerability

Improper authorization in Copilot Cowork allows an unauthorized attacker to elevate privileges over a network.

Microsoft Copilot Cowork

Aug 6, 2026

Revision history

2026-08-11 #2
Corrected CVE title. This is an informational change only.
2026-08-06 #1
Information published.

References

CVE-2026-59118 Copilot Cowork Elevation of Privilege Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-59118
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss