CVE-2026-20943: Microsoft Office Click-To-Run Remote Code Execution Vulnerability

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-13 · updated 2026-07-30
Weakness: CWE-426

Description

Untrusted search path in Microsoft Office allows an unauthorized attacker to execute code locally.

Affected products

Microsoft Office: 2016
Microsoft Office Deployment Tool: before 16.0.19426.20170 — fixed in 16.0.19426.20170
Microsoft SharePoint Server: before 16.0.19127.20442; 2016, 2019 — fixed in 16.0.19127.20442
Microsoft SharePoint Server Subscription Edition: from 16.0.0 before 16.0.19127.20442 — fixed in 16.0.19127.20442
Microsoft Office: from 16.0.0 before 16.0.5535.1000 — fixed in 16.0.5535.1000
Microsoft Office Deployment Tool: from 1.0 before 16.0.19426.20170 — fixed in 16.0.19426.20170
Microsoft Sharepoint Enterprise Server 2016: from 16.0.0 before 16.0.5535.1001 — fixed in 16.0.5535.1001
Microsoft SharePoint Server: from 16.0.0 before 16.0.10417.20083 — fixed in 16.0.10417.20083

How to fix

Upgrade to a fixed version: Microsoft Office Deployment Tool 16.0.19426.20170; Microsoft SharePoint Server 16.0.19127.20442; Microsoft SharePoint Server Subscription Edition 16.0.19127.20442; Microsoft Office 16.0.5535.1000; Microsoft Office Deployment Tool 16.0.19426.20170; Microsoft Sharepoint Enterprise Server 2016 16.0.5535.1001; Microsoft SharePoint Server 16.0.10417.20083. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943

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