CVE-2026-21531

moderate-risk
Published 2026-02-10

Deserialization of untrusted data in Azure SDK allows an unauthorized attacker to execute code over a network.

Do I need to act?

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0.48% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (3)

Azure Conversation Authoring Client Library
Azure Conversation Authoring Client Library
Azure Conversation Authoring Client Library

Affected Vendors

Microsoft

References (1)

Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21531
43
/ 100
moderate-risk
Severity 32/34 · Critical
Exploitability 2/34 · Minimal
Exposure 9/34 · Low