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Findings

CVE-2021-42292

Microsoft Excel Security Feature Bypass

Published Nov 9, 2021 · corrected/updated Aug 19, 2026 · microsoft 365 apps · evidence confidence very high

A security feature bypass vulnerability in Microsoft Excel would allow a local user to perform arbitrary code execution.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2021-42292 is a high public vulnerability record for microsoft 365 apps. CISA lists it as known exploited. Published remediation guidance: Apply updates per vendor instructions. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether microsoft 365 apps is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: microsoft/365 apps; microsoft/excel (2013); microsoft/excel (2016); microsoft/office (2013). Published remediation guidance: Apply updates per vendor instructions. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 7.8, EPSS 43.0%. CISA lists it as known exploited. Weakness classes: CWE-357. Sources contributing to this record: cisa_kev, cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Nov 17, 2021. Listed in the CISA Known Exploited Vulnerabilities catalog.

  • Patch and remediation

    Apply updates per vendor instructions. CISA due date Dec 1, 2021.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Nov 9, 2021 · Catalog

    Detected

    A security feature bypass vulnerability in Microsoft Excel would allow a local user to perform arbitrary code execution.

  2. Nov 17, 2021 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Dec 1, 2021 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Aug 19, 2026 · Catalog

    Updated

    A security feature bypass vulnerability in Microsoft Excel would allow a local user to perform arbitrary code execution.

Affected

  • cpe microsoft/365 appsversion unspecified
  • cpe microsoft/excel2013
  • cpe microsoft/excel2016
  • cpe microsoft/office2013
  • cpe microsoft/office2019
  • vendor Microsoft Officeversion unspecified

Sources

  • CISA KEVConfirmed exploitationCVE-2021-42292

    A security feature bypass vulnerability in Microsoft Excel would allow a local user to perform arbitrary code execution.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-42292

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-42292

    30-day exploitation probability 43.0%

    first.org
  • NIST NVDVulnerability recordCVE-2021-42292

    Microsoft Excel Security Feature Bypass Vulnerability

    nvd.nist.gov

References