Microsoft Office SharePoint · Cross-site Scripting
Source GCVE Database
Not known to be exploited · CVSS 9.0 Critical : upgrade to 16.0.20326.20278 as a priority.
Data as of 11 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (microsoft) | CVSS 3.1 | 9.0 |
|---|
- EPSS
- 0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 16.0.20326.20278
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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
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 11 Nov 2026.
What to do
Upgrade Microsoft SharePoint Server Subscription Edition to 16.0.20326.20278.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftMicrosoft SharePoint Server Subscription Edition | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, limit privileges of users to reduce risk and monitor for suspicious activity related to web page generation inputs.
Description
CVE-2026-109454 is a critical cross-site scripting (XSS) vulnerability in Microsoft Office SharePoint. It involves improper neutralization of input during web page generation, allowing an authorized attacker to perform spoofing attacks over a network. The vulnerability has a high CVSS score of 9.0, indicating severe impact on confidentiality, integrity, and availability.