CVE-2026-20963 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-20963CRITICAL

Microsoft SharePoint Remote Code Execution Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  H  H    9.8   .3155   98.1   YES

AFFECTED
  Product                                           Versions  Fixed
  Microsoft SharePoint Enterprise Server 2016       16.0.0 –  —
  Microsoft SharePoint Server 2019                  16.0.0 –  —
  Microsoft SharePoint Server Subscription Edition  16.0.0 –  —

TIMELINE
  Dec 4   Reserved by microsoft
  Mar 18  Added to CISA KEV, remediation due 2026-03-21
  Mar 18  Published (CNA: microsoft)

CWE-502 · CNA: microsoft · CVSS v3.1 · 2 references · KEV due March 21, 2026

Description

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 4, 2025	Reserved	Reserved by microsoft
March 18, 2026	KEV ADDED	Added to CISA KEV, remediation due 2026-03-21
March 18, 2026	Published	Published (CNA: microsoft)

Affected

Affected products and packages — 3 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Microsoft	Microsoft SharePoint Enterprise Server 2016	—	16.0.0	—
Microsoft	Microsoft SharePoint Server 2019	—	16.0.0	—
Microsoft	Microsoft SharePoint Server Subscription Edition	—	16.0.0	—

Weaknesses

CWE-502

References (2)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963 [vendor-advisory, patch]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20963 [government-resource]

Authoritative record: CVE-2026-20963 at cve.org

Vendors: microsoft

Weaknesses: CWE-502

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-20963 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.