CVE-2026-63520

HIGH

Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

CVSS v3.1 Score

8.1
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 8/11/2026Modified: 8/13/2026

Related Intelligence (3)

MEDIUMVulnerability

Rapid7 Analysis: Microsoft SharePoint Remote Code Execution (CVE-2026-63520)

CVE-2026-63520
Rapid7
CRITICALZero Day

Patch Tuesday - August 2026

Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday , including 236 vulnerabilities in Windows. This is lower volume than last month’s record-breaking behemoth, but still one of the largest Patch Tuesday totals ever. There is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for on

CVE-2026-63520CVE-2026-55040
Rapid7
CRITICALZero Day

CVE-2026-63520: Microsoft SharePoint Remote Code Execution (FIXED)

Overview Rapid7 Labs conducted a zero-day research project against Microsoft SharePoint, resulting in the discovery of two new vulnerabilities that, when chained together, achieve unauthenticated remote code execution (RCE) against a vulnerable SharePoint server. Today, both Rapid7 and Microsoft are disclosing the second vulnerability in this chain, the RCE vulnerability CVE-2026-63520. The first

CVE-2026-63520CVE-2026-55040
Rapid7

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63520PatchVendor Advisory