CVE-2025-47166: Microsoft SharePoint Enterprise Server 2016 · Deserialization of Untrusted Data
Affects Microsoft SharePoint Enterprise Server 2016Source CVE Database V5
Public exploit available (Exploit-DB) · 21% EPSS · CVSS 8.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 21.6% chance of exploitation in 30 days – higher than 97% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 10 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Microsoft Corporation
, 40 days before disclosure
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 2 hours after disclosure
First Exploit-DB entry (opens in a new tab)
Microsoft SharePoint 2019 - NTLM Authentication
, 22 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Microsoft SharePoint Enterprise Server 2016 | Affected
| Fixed in– |
AI-suggested
Until an official patch is released, organizations should implement specific mitigations to reduce risk. First, restrict and monitor access to SharePoint servers, ensuring only trusted and authorized personnel have privileges. Employ network segmentation and firewall rules to limit exposure of SharePoint services to untrusted networks. Enable and enforce strict input validation and logging on SharePoint to detect anomalous deserialization attempts. Use application whitelisting and endpoint protection solutions to detect and block suspicious code execution. Regularly audit SharePoint configurations and permissions to minimize attack surface. Consider deploying web application firewalls (WAFs) with custom rules to detect and block malicious serialized payloads. Prepare for rapid patch deployment by testing updates in controlled environments. Finally, maintain up-to-date backups and incident response plans to recover quickly if exploitation occurs.
Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.