What is the CVSS score of CVE-2026-20953?

CVE-2026-20953 has a CVSS 3.1 base score of 8.4 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of 365 Apps are affected by CVE-2026-20953?

Organizations using Use after free in Microsoft Office face notable risk from CVE-2026-20953, a use-after-free vulnerability rated CVSS 8.4.. A patch is available.

How to fix or mitigate CVE-2026-20953?

Within 7 days: Identify all affected systems and apply vendor patches promptly. If patching is delayed, consider network segmentation to limit exposure.

365 Apps CVE-2026-20953

HIGH

Use After Free (CWE-416)

2026-01-13 secure@microsoft.com

Microsoft Use After Free 365 Apps Office Long Term Servicing Channel Office

8.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.4 HIGH

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

ENISA EUVD

HIGH

qualitative

Primary rating from NVD.

CVSS VectorNVD

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

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 8.4

DescriptionCVE.org

Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

AnalysisAI

Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. [CVSS 8.4 HIGH]

Technical ContextAI

Classified as CWE-416 (Use After Free). Affects 365 Apps. Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

RemediationAI

Monitor vendor advisories for a patch.

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8.1

CVE-2026-20953 vulnerability details – vuln.today

Back

365 Apps CVE-2026-20953

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

More in 365 Apps

Same weakness CWE-416 – Use After Free

Same technique Use After Free

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External POC / Exploit Code