CVE-2026-45659 — 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-2026-45659HIGH

Microsoft SharePoint Remote Code Execution Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   N  U  H  H  H    8.8   .0986   95.2   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
  May 12  Reserved by microsoft
  Jul 1   Added to CISA KEV, remediation due 2026-07-04
  Jul 1   Published (CNA: microsoft)
  Jul 5   DUE DATE PASSED — CVE-2026-45659 (Microsoft SharePoint Enterprise Server 2016). CISA remediation deadline was July 4, 2026; still in catalog.
  Jul 23  ENRICHED — CVE-2026-45659 (Microsoft SharePoint Server). Received CVSS 8.8 and CPE data from NVD.

CWE-502 · CNA: microsoft · CVSS v3.1 · 2 references · NVD status: Analyzed · KEV due July 4, 2026

Description

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

Lifecycle

Complete event history — 5 events, chronological
Date	Event	Detail
May 12, 2026	Reserved	Reserved by microsoft
July 1, 2026	KEV ADDED	Added to CISA KEV, remediation due 2026-07-04
July 1, 2026	Published	Published (CNA: microsoft)
July 5, 2026	DUE DATE PASSED	DUE DATE PASSED — CVE-2026-45659 (Microsoft SharePoint Enterprise Server 2016). CISA remediation deadline was July 4, 2026; still in catalog.
July 23, 2026	ENRICHED	ENRICHED — CVE-2026-45659 (Microsoft SharePoint Server). Received CVSS 8.8 and CPE data from NVD.

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-2026-45659 [Vendor Advisory]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45659 [US Government Resource]

Authoritative record: CVE-2026-45659 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-2026-45659 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.