Critical severity · published Aug 11, 2026
CVE-2026-70306
Microsoft Office SharePoint Spoofing Vulnerability
9.3
CVSS
1%
EPSS
No
On KEV
Description
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 63% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SH
SharePoint · Microsoft
before 16.0.19725.20434; 2016; 2019 · source: NVD
MS
Microsoft SharePoint Enterprise Server 2016 · Microsoft
16.0.0 before 16.0.5565.1001 · source: vendor
MS
Microsoft SharePoint Server 2019 · Microsoft
16.0.0 before 16.0.10417.20198 · source: vendor
MS
Microsoft SharePoint Server Subscription Edition · Microsoft
16.0.0 before 16.0.19725.20522 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-70306
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-70306
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70306
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