Use After Free in Microsoft 365 Apps
CVE-2026-20952
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- Microsoft 365 Apps
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Office 2016 — versions 16.0.0
- Microsoft Office 2019 — versions 19.0.0
- Microsoft Office Ltsc 2021 — versions 16.0.1
- Microsoft Office Ltsc 2024 — versions 16.0.0
- Microsoft Office Ltsc For Mac 2021 — versions 16.0.1
- Microsoft Office Ltsc For Mac 2024 — versions 16.0.0
- Microsoft Office — versions 2016, 2019
- Microsoft Office Long Term Servicing Channel — versions 2021, 2024
Weakness classification (CWE)
References
- Microsoft Office Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20952?
- CVE-2026-20952 is a high-severity vulnerability in Microsoft 365 Apps, classified under Use After Free. CVSS score: 8.4/10. Published 2026-01-13.
- How severe is CVE-2026-20952?
- High severity. CVSS v3 base score is 8.4 out of 10.