CVE-2026-62873

criticalCVSS 9.8covered by 2 sourcesfirst seen 2026-08-06

Improper verification of cryptographic signature in Microsoft 365 Admin Center allows an unauthorized attacker to elevate privileges over a network.

CSIRTS triage

What: Improper verification of cryptographic signatures allows unauthorized privilege escalation over a network.
Who is affected: All Microsoft 365 Admin Center deployments are affected.
Urgency: Critical severity (CVSS 9.8) with no current exploitation reported; urgent patching essential.
Action: Apply Microsoft security updates for 365 Admin Center and validate signature verification implementation.

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