CVE-2026-62827: Microsoft SharePoint Server Elevation of Privilege Vulnerability
CVE-2026-62827 is an elevation of privilege vulnerability in Microsoft SharePoint Server, rated Critical by Microsoft, with a CVSS 3.1 base score of 8.8 (High). An attacker can exploit it remotely over the network, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 0.94% probability of exploitation activity in the next 30 days, higher than 61% of all scored vulnerabilities. Microsoft released the fix on 11 August 2026 in the August 2026 Patch Tuesday, delivered through 5 security updates (KB5002905, KB5002906, KB5002894, KB5002896 and more). It affects 3 products in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2026-62827
- Severity
- High CVSS 8.8
- Microsoft severity
- Critical
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-287
- EPSS
- 0.94% (percentile 61%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- August 2026 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2026-62827 at 8.8 (temporal 7.7) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Improper authentication in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?
Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order.
I am running SharePoint Server 2016. Do the updates for SharePoint Enterprise Server 2016 also apply to the version I am running?
Yes. The same KB number applies to both SharePoint Server 2016 and SharePoint Enterprise Server 2016. Customers running either version should install the security update to be protected from this vulnerability.
How could an attacker exploit the vulnerability?
An authenticated attacker with access to the domain could perform remote code execution on the SharePoint server to elevate themselves to SharePoint admin.
Affected products (3)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft SharePoint Enterprise Server 2016 | KB5002905 KB5002906 | Security Update Security Update | 16.0.5565.1001 16.0.5565.1001 | Maybe Maybe |
| Microsoft SharePoint Server 2019 | KB5002894 KB5002896 | Security Update Security Update | 16.0.10417.20198 16.0.10417.20198 | Maybe Maybe |
| Microsoft SharePoint Server Subscription Edition | KB5002893 | Security Update | 16.0.19725.20522 | Maybe |
Security updates (5)
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 8.8 (HIGH)
- NVD weakness
- CWE-287
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| sharepoint server | before 16.0.19725.20522 |
| sharepoint server 2016 | all listed versions |
| sharepoint server 2019 | all listed versions |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62827 (Patch, Vendor Advisory)
Acknowledgments
- Ivan Vagunin
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |