CVE-2026-45659: listed in the CISA KEV catalog

CVE-2026-45659 · CVSS 8.8 HIGH · EPSS 3% · KEV 2026-07-01 · patch available

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

Is CVE-2026-45659 exploited?

• Listed in the CISA KEV catalog on 2026-07-01.
• Federal remediation due 2026-07-04.
• Past that date by 88 days.
• EPSS puts exploitation in the next 30 days at 3%.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

• Microsoft · Microsoft SharePoint Enterprise Server 2016 · < 16.0.5552.1002
• Microsoft · Microsoft SharePoint Server 2019 · < 16.0.10417.20128
• Microsoft · Microsoft SharePoint Server Subscription Edition · < 16.0.19725.20280

Is there a patch?

• KB5002868
• KB5002870
• KB5002863

What PlainSec published about CVE-2026-45659

• SharePoint PoC Lowers the Bar for RCE (2026-08-27)
• Site Member Access Can Break SharePoint (2026-05-27)

Primary sources

• NVD record
• CISA KEV catalog
• Microsoft KB5002868
• Microsoft KB5002870
• Microsoft KB5002863

KEV and EPSS are re-checked daily. Record last updated 2026-09-24.