What is the CVSS score of CVE-2026-20956?

CVE-2026-20956 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of 365 Apps are affected by CVE-2026-20956?

Organizations using Untrusted pointer dereference in Microsoft Office Excel face notable risk from CVE-2026-20956 rated CVSS 7.8. Exploitation could compromise the security of affected deployments.. A patch is available.

How to fix or mitigate CVE-2026-20956?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

365 Apps CVE-2026-20956

HIGH

Untrusted Pointer Dereference (CWE-822)

2026-01-13 secure@microsoft.com

Microsoft 365 Apps Office Long Term Servicing Channel

7.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.8 HIGH

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

ENISA EUVD

HIGH

qualitative

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

CVE Published

Jan 13, 2026 - 18:16 nvd

HIGH 7.8

DescriptionCVE.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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CVE-2026-20956 vulnerability details – vuln.today

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365 Apps CVE-2026-20956

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

More in 365 Apps

Same weakness CWE-822 – Untrusted Pointer Dereference

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External POC / Exploit Code