CVE-2026-45659
HIGH 8.8 KNOWN EXPLOITEDDeserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
ACTIVELY EXPLOITED
Confirmed exploited in the wild — in CISA KEV since 2026-07-01. Patch or mitigate now.
Exploitation likelihood
2.8%chance of exploitation in 30 days · 85th percentile
● In CISA KEV (2026-07-01)
○ 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: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Affected
Vendors Microsoft
Products Microsoft Sharepoint Enterprise Server 2016 Microsoft Sharepoint Server 2019 Microsoft Sharepoint Server Subscription Edition
Weakness (CWE)
- CWE-502: Deserialization of untrusted data
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C