CVE-2026-108428
HIGH 8.8Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
ELEVATED IMPACT
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.5%chance of exploitation in 30 days · 38th percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
8.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓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-2026-108428/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-2026-108428/poc.json
Affected
Vendors Microsoft
Products Microsoft 365 Apps For Enterprise Microsoft Office Ltsc 2021 Microsoft Office Ltsc 2024 365 Apps Office 2021 Office 2024
Weakness (CWE)
- CWE-122: : Heap-based Buffer Overflow
CVSS vector
CVSS:3.1/AV:N/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 2021 | * |
| Microsoft | Office 2021 | * |
| Microsoft | Office 2024 | * |
| Microsoft | Office 2024 | * |
All CVSS metrics
- HIGH 8.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H