---
title: "CVE-2026-32201: Microsoft SharePoint Server Improper Input Validation Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-32201/
description: "CVE-2026-32201 (Microsoft SharePoint Server): Exploited in the wild (CISA KEV). Improper input validation in Microsoft Office SharePoint allows an…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-14
date_modified: 2026-10-15
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-32201"
kev: true
cvss: 6.5
epss: 0.43378
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-32201: Microsoft SharePoint Server Improper Input Validation Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Microsoft SharePoint Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-04-14, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-04-28 ; treat that as the outer limit, not the target.
- EPSS 43.4% , percentile 99: FIRST’s model estimates a 43.4% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.

## Affected products (CVE record)

- Microsoft Microsoft SharePoint Enterprise Server 2016: 16.0.0 < 16.0.5548.1003
- Microsoft Microsoft SharePoint Server 2019: 16.0.0 < 16.0.10417.20114
- Microsoft Microsoft SharePoint Server Subscription Edition: 16.0.0 < 16.0.19725.20210

## Severity

- microsoft CVSS 3.1: 6.5 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:F/RL:O/RC:C`

## Exploitation

- CISA KEV: added 2026-04-14; federal due date 2026-04-28. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 43.38% probability of exploitation activity in the next 30 days; percentile 99.

## Sources

- [Microsoft SharePoint Server Spoofing Vulnerability](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32201)
- [Listed in CISA KEV notes (msrc.microsoft.com)](https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-32201)
- [CVE.org record CVE-2026-32201](https://www.cve.org/CVERecord?id=CVE-2026-32201)
- [NVD entry CVE-2026-32201](https://nvd.nist.gov/vuln/detail/CVE-2026-32201)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-32201)

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Source page: https://erroneo.us/security/cve/CVE-2026-32201/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt