Vulnerability in Microsoft 365 Apps
CVE-2026-45459
Protection mechanism failure in Microsoft Office Excel allows an unauthorized attacker to bypass a security feature locally.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (38.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Microsoft 365 Apps
- Microsoft 365
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Office 365 For Mac — versions 1.0.0
- 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 2021
- Microsoft Office 2024
Weakness classification (CWE)
References
- Microsoft Excel Security Feature Bypass Vulnerability (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-45459?
- CVE-2026-45459 is a low-severity vulnerability in Microsoft 365 Apps, classified under Protection Mechanism Failure. CVSS score: 3.3/10. Published 2026-06-09.
- How severe is CVE-2026-45459?
- Low severity. CVSS v3 base score is 3.3 out of 10.