Microsoft Security Update Guide · Copilot
Copilot Studio Elevation of Privilege Vulnerability
Published
What does this mean?
- Elevation of Privilege. An attacker can gain more rights than they should have, for example admin rights.
- It can be exploited over the network (including from the internet if the service is reachable there), without an account and without any user action.
- CVSS 9.3 out of 10: critical. Microsoft rates it Critical.
- What should you do? Nothing: Microsoft fixed this in the cloud service. There is no update to install.
Improper verification of cryptographic signature in Copilot Studio allows an unauthorized attacker to elevate privileges over a network.
What kind of flaw is this?
- CWE-347: Improper Verification of Cryptographic Signature
A digital signature is not verified correctly.
Key facts
Released
8 sep 2026
Impact
Elevation of Privilege
Max severity
Critical
Weakness
CVSS 3.1
9.3 / 8.1 (base / temporal)
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N/E:U/RL:O/RC:CPublicly disclosed
No
Exploited
No
Exploitability assessment
N/A
Customer action required
No, fixed by Microsoft
Links
CVSS metrics
| Base score metrics | |
|---|---|
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Changed |
| Confidentiality | Low |
| Integrity | High |
| Availability | None |
| Temporal score metrics | |
| Exploit Code Maturity | Unproven |
| Remediation Level | Official Fix |
| Report Confidence | Confirmed |
Affected products and updates
| Product | Update | Build |
|---|---|---|
| Microsoft Copilot Studio | — | — |
FAQ
- 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.
Revisions
| Version | Date | Note |
|---|---|---|
| 1 | 8 sep 2026 | Information published. |
This is in the weekly digest for week 37 · What changed this week? →
View at Microsoft → ← All security advisories
Source: Microsoft Security Update Guide. 365Fanatic is not affiliated with Microsoft.
