May 2026 Patch Tuesday: what Security and IT teams should prioritise

The operational queue contains 116 approved patch records linked to 183 unique CVEs. No records in the approved cohort currently carry an accelerated or out-of-band assessment. BlackTree urgency is separate from vendor severity, CVSS and EPSS.

Security teams should start with confirmed exploitation and exposed control-plane systems. IT administrators should then review applicability, prerequisites, restart impact, sequencing, known issues and rollback guidance on each patch detail page.

Most important Microsoft patches this month

The following fixes deserve early attention based on confirmed exploitation, public disclosure, attack path and technical impact. Applicability still depends on the products and roles deployed in each environment.

• CVE-2026-41089: Windows Netlogon Remote Code Execution Vulnerability Its CVSS vector describes a network attack that needs neither privileges nor user interaction. Critical, CVSS 9.8.
• CVE-2026-41096: Windows DNS Client Remote Code Execution Vulnerability Its CVSS vector describes a network attack that needs neither privileges nor user interaction. Critical, CVSS 9.8.
• CVE-2026-42898: Microsoft Dynamics 365 On-Premises Remote Code Execution Vulnerability Successful exploitation can run attacker-controlled code in the affected component. Critical, CVSS 9.9.
• CVE-2026-40365: Microsoft SharePoint Server Remote Code Execution Vulnerability Successful exploitation can run attacker-controlled code in the affected component. Critical, CVSS 8.8.

Open the canonical May 2026 Patch Tuesday action queue on cve.blacktree.nl.

Patch details and exploitation assessments were checked against the Microsoft Security Update Guide release data for May 2026.

Editorial article generated from approved catalogue data. Recheck the canonical cycle for later vendor revisions or BlackTree corrections.