CVE-2026-21531

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

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

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

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta1::::python::*
	cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta2::::python::*
	cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta3::::python::*

History

17 Jun 2026, 10:18

Type	Values Removed	Values Added
Summary		(es) Deserialización de datos no confiables en el SDK de Azure permite a un atacante no autorizado ejecutar código a través de una red.

12 Feb 2026, 15:49

Type	Values Removed	Values Added
CPE		cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta3::::python::* cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta1::::python::* cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta2::::python::*
References	~~() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21531 -~~	() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21531 - Vendor Advisory
First Time		Microsoft azure Conversation Authoring Client Library Microsoft

10 Feb 2026, 18:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-02-10 18:16

Updated : 2026-06-17 10:18

NVD link : CVE-2026-21531

Mitre link : CVE-2026-21531

CVE.ORG link : CVE-2026-21531

JSON object : View

Products Affected

microsoft

azure_conversation_authoring_client_library

CWE

CWE-502

Deserialization of Untrusted Data

{"id": "CVE-2026-21531", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-21531", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-02-11T04:56:07.295834Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secure@microsoft.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "affected": [{"source": "secure@microsoft.com", "affectedData": [{"vendor": "Microsoft", "product": "Azure AI Language Authoring", "versions": [{"status": "affected", "version": "1.0.0", "lessThan": "1.0.0b4", "versionType": "custom"}]}]}], "published": "2026-02-10T18:16:35.580", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21531", "tags": ["Vendor Advisory"], "source": "secure@microsoft.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "secure@microsoft.com", "description": [{"lang": "en", "value": "CWE-502"}]}], "descriptions": [{"lang": "en", "value": "Deserialization of untrusted data in Azure SDK allows an unauthorized attacker to execute code over a network."}, {"lang": "es", "value": "Deserializaci\u00f3n de datos no confiables en el SDK de Azure permite a un atacante no autorizado ejecutar c\u00f3digo a trav\u00e9s de una red."}], "lastModified": "2026-06-17T10:18:47.720", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta1:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "5F0D2A31-6685-4968-B9BD-8538BD0CD134"}, {"criteria": "cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta2:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "6083B261-3037-4BFB-ACC5-B8945AE1046F"}, {"criteria": "cpe:2.3:a:microsoft:azure_conversation_authoring_client_library:1.0.0:beta3:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "CF3829C8-635B-4E0B-9C39-9FEA1A595C57"}], "operator": "OR"}]}], "sourceIdentifier": "secure@microsoft.com"}