Microsoft Office SharePoint Spoofing Vulnerability

published 2026-10-13 26 d ago modified 2026-10-31 8 d ago also EUVD-2026-99740

cvss: 4.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.

Patch / fix

fixed in 1 links 1

Microsoft Microsoft SharePoint Server Subscription Edition 16.0.20326.20190

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88209 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 26 d ago (2026-10-13)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C
CNA	3.1	4.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Affected products

Microsoft Microsoft SharePoint Server Subscription Edition

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

msrc.microsoft.com /update-guide/vulnerability/CVE-2026-88209
vendor-advisory, patch

Sources

CVE List CVE-2026-88209
NVD CVE-2026-88209

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary