365 Apps
CVE-2026-20956
HIGH
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Primary rating from NVD.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
AnalysisAI
Memory corruption in Microsoft Excel within Office 365 Apps and Long Term Servicing Channel enables local code execution through a malicious file requiring user interaction. An attacker can achieve arbitrary code execution with full system privileges by exploiting improper pointer handling in the application. No patch is currently available, leaving affected systems vulnerable until Microsoft releases a fix.
Technical ContextAI
Affects 365 Apps. Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
RemediationAI
Monitor vendor advisories for a patch.
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Same weakness CWE-822 – Untrusted Pointer Dereference
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External POC / Exploit Code
Leaving vuln.today