CVE-2026-50522: listed in the CISA KEV catalog

CVE-2026-50522 · CVSS 9.8 CRITICAL · KEV 2026-07-22 · patch available

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

Is CVE-2026-50522 exploited?

• Listed in the CISA KEV catalog on 2026-07-22.
• Federal remediation due 2026-07-25.
• Past that date by 68 days.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

• Microsoft · Microsoft SharePoint Enterprise Server 2016 · < 16.0.5561.1001
• Microsoft · Microsoft SharePoint Server 2019 · < 16.0.10417.20175
• Microsoft · Microsoft SharePoint Server Subscription Edition · < 16.0.19725.20434

Is there a patch?

• KB5002891
• KB5002883
• KB5002882

What PlainSec published about CVE-2026-50522

• SharePoint Patches Didn’t Clear BIT’s Breach (2026-08-10)
• SharePoint Patch Leaves Trusted Access Behind (2026-07-21)

Primary sources

• NVD record
• CISA KEV catalog
• Microsoft KB5002891
• Microsoft KB5002883
• Microsoft KB5002882

What this record does not say

• No EPSS score.

KEV and EPSS are re-checked daily. Record last updated 2026-08-27.