CVE-2026-33843Network attack vector

Unauthenticated privilege elevation via alternate authentication path

Published May 22, 2026 · Updated May 22, 2026

Authentication bypass in Microsoft Azure Active Directory B2C allows remote attackers to elevate privileges over a network. Microsoft identifies an alternate authentication path or channel but has not disclosed the affected endpoint, protocol flow, or missing validation. No prior privileges or user interaction are required; successful exploitation compromises confidentiality and integrity, while availability is unaffected.

CVSS severity9.1
Critical
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Microsoft Azure Active Directory B2C allows remote attackers to elevate privileges over a network. Microsoft identifies an alternate authentication path or channel but has not disclosed the affected endpoint, protocol flow, or missing validation. No prior privileges or user interaction are required; successful exploitation compromises confidentiality and integrity, while availability is unaffected.

The record

CVE
CVE-2026-33843
Published
May 22, 2026
Updated
May 22, 2026
Vendor
Microsoft
Product
Azure Active Directory B2C
Classifications
CWE-288, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 22, 2026CVE publishedPublication date reported by the CVE source.
  2. May 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=-

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Azure Active Directory B2Cversion=-

Published CVSS scores

9.1Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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