CVE-2026-55021 json
Microsoft SharePoint Server Spoofing Vulnerability
published 2026-07-14 3 mo ago modified 2026-11-01 8 d ago also EUVD-2026-44166
- cvss
- 7.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
Summary
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
- Microsoft Microsoft SharePoint Enterprise Server 2016 16.0.5561.1001
- Microsoft Microsoft SharePoint Server 2019 16.0.10417.20175
- Microsoft Microsoft SharePoint Server Subscription Edition 16.0.19725.20434
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C |
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
| NVD | 3.1 | 8.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
Affected products
- Microsoft Microsoft SharePoint Enterprise Server 2016
- Microsoft Microsoft SharePoint Server 2019
- 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-2026-55021
vendor-advisory, patch
Sources
- CVE List CVE-2026-55021
- NVD CVE-2026-55021
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