VulnerabilityAnalyzed
CVE-2026-66805
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
HIGH 8.8EPSS 2.04%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.04%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.04% probability · 81th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-502
- Affected
- microsoft/sharepoint server
- Source
- secure@microsoft.com
EPSS 2.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66805Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.