MSRC_CVE-2026-26144

Vulnerability from csaf_microsoft - Published: 2026-03-10 07:00 - Updated: 2026-03-10 07:00
Summary
Microsoft Excel Information Disclosure Vulnerability

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
Required. The vulnerability documented by this CVE requires customer action to resolve.
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{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Anonymous"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Critical"
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    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    "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-2026-26144 Microsoft Excel Information Disclosure Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26144"
      },
      {
        "category": "self",
        "summary": "CVE-2026-26144 Microsoft Excel Information Disclosure Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26144.json"
      },
      {
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        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
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        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Microsoft Excel 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"
        }
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      "id": "msrc_CVE-2026-26144",
      "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": [
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        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003chttps://aka.ms/OfficeSecurityReleases",
            "product": {
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            }
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            }
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            }
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        ],
        "category": "product_name",
        "name": "Microsoft 365 Apps for Enterprise for 32-bit Systems"
      }
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  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-26144",
      "cwe": {
        "id": "CWE-79",
        "name": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "No, the Preview Pane is not an attack vector.",
          "title": "Is the Preview Pane an attack vector for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited this vulnerability could potentially cause Copilot Agent mode to exfiltrate data via unintended network egress, enabling zero-click information disclosure attack",
          "title": "What type of information could be disclosed by this vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "11762",
          "11763"
        ],
        "known_affected": [
          "1",
          "2"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-26144 Microsoft Excel Information Disclosure Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26144"
        },
        {
          "category": "self",
          "summary": "CVE-2026-26144 Microsoft Excel Information Disclosure Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26144.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-03-10T07:00:00.000Z",
          "details": "https://aka.ms/OfficeSecurityReleases:Security Update:https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates",
          "product_ids": [
            "1",
            "2"
          ],
          "url": "https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
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      ],
      "threats": [
        {
          "category": "impact",
          "details": "Information Disclosure"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Unlikely"
        }
      ],
      "title": "Microsoft Excel Information Disclosure Vulnerability"
    }
  ]
}


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Sightings

Author Source Type Date

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.