CVE-2026-63525
HIGH 7.8Numeric truncation error in Microsoft Office Word allows an unauthorized attacker to execute code locally.
ELEVATED IMPACT
Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 31st percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
7.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ✓Privileges: No account or privileges required
- ⚠User interaction: A user must take an action (click / open a file)
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-63525/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-63525/poc.json
Affected
Vendors Microsoft
Products Microsoft 365 Apps For Enterprise Microsoft Office 2019 Microsoft Office Ltsc 2021 Microsoft Office Ltsc 2024 Microsoft Word 2016 365 Apps Office 2019 Office 2021 Office 2024 Word
Weakness (CWE)
- CWE-197: : Numeric Truncation Error
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | 365 Apps | * |
| Microsoft | 365 Apps | * |
| Microsoft | Office 2019 | * |
| Microsoft | Office 2019 | * |
| Microsoft | Office 2021 | * |
| Microsoft | Office 2021 | * |
| Microsoft | Office 2024 | * |
| Microsoft | Office 2024 | * |
| Microsoft | Word | 2016 |
| Microsoft | Word | 2016 |
All CVSS metrics
- HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H