CVE-2026-65667: Microsoft Teams Elevation of Privilege Vulnerability
CVE-2026-65667 is an elevation of privilege vulnerability in Microsoft Teams, rated Critical by Microsoft, with a CVSS 3.1 base score of 10 (Critical). An attacker can exploit it remotely over the network, without any privileges and without user interaction. Microsoft has not reported exploitation in the wild. The EPSS model estimates a 0.80% probability of exploitation activity in the next 30 days, higher than 57% of all scored vulnerabilities. Microsoft published it on 6 August 2026, outside Patch Tuesday. It affects 1 product in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2026-65667
- Severity
- Critical CVSS 10
- Microsoft severity
- Critical
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Weakness
- CWE-862
- EPSS
- 0.80% (percentile 57%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- August 2026 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2026-65667 at 10 (temporal 8.7) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | None |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Missing authorization in Microsoft Teams allows an unauthorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
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.
Affected products (1)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Teams |
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 10 (CRITICAL)
- NVD weakness
- CWE-862
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| teams | all listed versions |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65667 (Vendor Advisory)
Acknowledgments
- Henrique Pereira with Microsoft
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |