{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "\u003ca href=\"https://linkedin.com/in/khaledsec\"\u003eKhaled Mohamed\u003c/a\u003e"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "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": "Required. The vulnerability documented by this CVE requires 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-2026-26123 Microsoft Authenticator Information Disclosure Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26123"
      },
      {
        "category": "self",
        "summary": "CVE-2026-26123 Microsoft Authenticator Information Disclosure Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26123.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "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 Authenticator Information Disclosure Vulnerability",
    "tracking": {
      "current_release_date": "2026-03-10T07:00:00.000Z",
      "generator": {
        "date": "2026-03-10T17:04:32.315Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-26123",
      "initial_release_date": "2026-03-10T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-03-10T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c6.2511.7533",
            "product": {
              "name": "Microsoft Authenticator for Android \u003c6.2511.7533",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "6.2511.7533",
            "product": {
              "name": "Microsoft Authenticator for Android 6.2511.7533",
              "product_id": "12289"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Authenticator for Android"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c6.8.40",
            "product": {
              "name": "Microsoft Authenticator for IOS \u003c6.8.40",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "6.8.40",
            "product": {
              "name": "Microsoft Authenticator for IOS 6.8.40",
              "product_id": "20927"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Authenticator for IOS"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-26123",
      "cwe": {
        "id": "CWE-939",
        "name": "Improper Authorization in Handler for Custom URL Scheme"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "User interaction is required because the user must have a malicious application installed on their device and then accidentally select that application as the handler for the sign\u2011in deep link. This can occur when the user scans a QR code or taps a sign\u2011in link and chooses the malicious app instead of Microsoft Authenticator, causing the sign\u2011in flow to be handled by the attacker\u2011controlled app.",
          "title": "According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?"
        },
        {
          "category": "faq",
          "text": "This vulnerability could result in disclosure of a one\u2011time sign\u2011in code or authentication deep link if the user selects a malicious application as the handler. The malicious app would receive the sign\u2011in information and could potentially use it to authenticate as the user, allowing access to information or services available to that account.",
          "title": "What type of information could be disclosed by this vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "12289",
          "20927"
        ],
        "known_affected": [
          "1",
          "2"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-26123 Microsoft Authenticator Information Disclosure Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26123"
        },
        {
          "category": "self",
          "summary": "CVE-2026-26123 Microsoft Authenticator Information Disclosure Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26123.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-03-10T07:00:00.000Z",
          "details": "6.2511.7533:Security Update:https://play.google.com/store/apps/details?id=com.azure.authenticator\u0026hl=en_US",
          "product_ids": [
            "2"
          ],
          "url": "https://play.google.com/store/apps/details?id=com.azure.authenticator\u0026hl=en_US"
        },
        {
          "category": "vendor_fix",
          "date": "2026-03-10T07:00:00.000Z",
          "details": "6.8.40:Security Update:https://apps.apple.com/us/app/microsoft-authenticator/id983156458",
          "product_ids": [
            "1"
          ],
          "url": "https://apps.apple.com/us/app/microsoft-authenticator/id983156458"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 4.8,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Information Disclosure"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft Authenticator Information Disclosure Vulnerability"
    }
  ]
}