Improper input validation in Microsoft Sharepoint Enterprise Server 2016

CVE-2026-63520

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

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (59.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 59.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-63520: fell from 0.029 to 0.010.

EPSS over last 30 days · oldest: 0.029 · newest: 0.010 · change: -0.019

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-63520?
CVE-2026-63520 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Improper Input Validation. CVSS score: 8.1/10. Published 2026-08-11.
How severe is CVE-2026-63520?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2026-63520 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.