CVE-2026-20949

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{}

{"analysis": {"en": {"generated_at": "2026-04-16T08:02:36.874011+00:00", "value": {"mitigation_remediation": ["Apply the latest Microsoft Office security update from the official update guide linked in the advisory.", "If a patch cannot be applied immediately, disable or modify the vulnerable security feature, for example by adjusting macro settings or running Excel in Safe Mode.", "Run all Excel workbooks through a reputable antivirus or endpoint protection before opening them."], "summary": {"action": "Patch ASAP", "impact": "Local security feature bypass in Microsoft Excel"}, "threat_synthesis": {"affected_systems": "The vulnerability affects Microsoft 365 Apps for Enterprise, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, and Microsoft Office LTSC for Mac 2024. Both 32\u2011bit and 64\u2011bit Windows installations and macOS versions are affected; no specific version numbers are listed, indicating that all releases within the mentioned product lines are impacted.", "description_and_impact": "Improper access control in Microsoft Office Excel enables an unauthorized attacker to bypass a built\u2011in security feature when the application is run locally. This bypass can allow local users or malware that has local execution privileges to elevate privileges or execute malicious code that would normally be blocked by the security feature. The impact is a loss of integrity and confidentiality of data processed by or stored in affected Excel workbooks.", "risk_and_exploitability": "With a CVSS score of 7.8 the vulnerability is high, and the EPSS score of less than 1% indicates a very low but nonzero probability of exploitation. It is not currently listed in the CISA KEV catalog. The likely attack vector is local, requiring access to a machine with an affected version of Excel; the attacker can supply a crafted workbook or command to bypass the security guard. Because the feature is bypassed locally, the risk is focused on end\u2011user workstations rather than remote denial of service."}}}}, "created": "2026-04-16T08:15:29.657833+00:00", "updated": "2026-04-16T08:15:29.657845+00:00", "vendors": []}