CVE-2026-21531

Name: CVE-2026-21531
Creator: NVD / NIST
Published: 2026-02-10T18:16:35.58+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.34%

Last modified Jun 17, 2026

CVE-2026-21531 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Deserialization of untrusted data in Azure SDK allows an unauthorized attacker to execute code over a network.. EPSS estimates a 2.34% chance of exploitation in the next 30 days.

Description

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

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.34%

81.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-502

Affected Software

Vendor	Product	Versions	Update
Microsoft	Azure Conversation Authoring Client Library	1.0.0	Beta1

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21531Vendor Advisory

Timeline

Published: Feb 10, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-21531?

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

How severe is CVE-2026-21531?

CVE-2026-21531 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.34% probability of exploitation in the next 30 days.

How do I fix CVE-2026-21531?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-21531?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST