Vulnerability-Lookup

CVE-2026-33843 (GCVE-0-2026-33843)

Vulnerability from cvelistv5 – Published: 2026-05-22 22:03 – Updated: 2026-05-22 22:03 Exclusively Hosted Service

Title

Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability

Summary

Authentication bypass using an alternate path or channel in Microsoft Azure Active Directory B2C allows an unauthorized attacker to elevate privileges over a network.

Severity ?

9.1 (Critical)


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

CWE

CWE-288 - Authentication Bypass Using an Alternate Path or Channel

Assigner

microsoft

References

1 reference

URL	Tags
https://msrc.microsoft.com/update-guide/vulnerabi…	vendor-advisorypatch

Impacted products

1 product

Vendor	Product	Version
Microsoft	Microsoft Entra	Affected: -

Date Public ?

2026-05-21 14:00

Show details on NVD website

JSON

To clipboard

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      "affected": [
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      "descriptions": [
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          "lang": "en-US",
          "value": "Authentication bypass using an alternate path or channel in Microsoft Azure Active Directory B2C allows an unauthorized attacker to elevate privileges over a network."
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      "providerMetadata": {
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        "shortName": "microsoft"
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      "tags": [
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      "title": "Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability"
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    "datePublished": "2026-05-22T22:03:10.460Z",
    "dateReserved": "2026-03-24T00:52:01.354Z",
    "dateUpdated": "2026-05-22T22:03:10.460Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-33843",
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      "percentile": "0.15735"
    }
  }
}

MSRC_CVE-2026-33843

Vulnerability from csaf_microsoft - Published: 2026-05-12 07:00 - Updated: 2026-05-21 07:00

Summary

Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability

Severity

Critical

Notes

Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Customer Action: Not required. The vulnerability documented by this CVE requires no customer action to resolve.

CVE-2026-33843

9.1 (Critical)


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

CWE-288 - Authentication Bypass Using an Alternate Path or Channel

Affected products

Fixed 1 product

Product	Identifier	Version	Remediation
Microsoft Entra ID		—

Threats

Impact Elevation of Privilege

Exploit Status Publicly Disclosed:No;Exploited:No

References

7 references

URL	Category
https://msrc.microsoft.com/update-guide/vulnerabi…	self
https://msrc.microsoft.com/csaf/advisories/2026/m…	self
https://www.microsoft.com/en-us/msrc/exploitabili…	external
https://support.microsoft.com/lifecycle	external
https://www.first.org/cvss	external
https://msrc.microsoft.com/update-guide/vulnerabi…	self
https://msrc.microsoft.com/csaf/advisories/2026/m…	self

Acknowledgments

<a href="https://securesaml.com/">Alexander Tan</a> with SecureSAML

JSON

To clipboard

{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "\u003ca href=\"https://securesaml.com/\"\u003eAlexander Tan\u003c/a\u003e with SecureSAML"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Critical"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
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      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    },
    "lang": "en-US",
    "notes": [
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        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      },
      {
        "category": "general",
        "text": "Not required. The vulnerability documented by this CVE requires no customer action to resolve.",
        "title": "Customer Action"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-33843 Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33843"
      },
      {
        "category": "self",
        "summary": "CVE-2026-33843 Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-33843.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
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        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability",
    "tracking": {
      "current_release_date": "2026-05-21T07:00:00.000Z",
      "generator": {
        "date": "2026-05-22T01:25:43.831Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-33843",
      "initial_release_date": "2026-05-12T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-21T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
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        "category": "product_name",
        "name": "Microsoft Entra ID",
        "product": {
          "name": "Microsoft Entra ID",
          "product_id": "12383"
        }
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-33843",
      "cwe": {
        "id": "CWE-288",
        "name": "Authentication Bypass Using an Alternate Path or Channel"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "This vulnerability has already been fully mitigated by Microsoft. There is no action for users of this service to take. The purpose of this CVE is to provide further transparency.\nPlease see Toward greater transparency: Unveiling Cloud Service CVEs for more information.",
          "title": "Why are there no links to an update or instructions with steps that must be taken to protect from this vulnerability?"
        }
      ],
      "product_status": {
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        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-33843 Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33843"
        },
        {
          "category": "self",
          "summary": "CVE-2026-33843 Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-33843.json"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 9.1,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "products": [
            "12383"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Elevation of Privilege"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No"
        }
      ],
      "title": "Microsoft Azure Active Directory B2C Elevation of Privilege Vulnerability"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-33843 (GCVE-0-2026-33843)

MSRC_CVE-2026-33843

Tags

Sightings

Nomenclature