Security Digest · Vulnerability record · Known exploited
CVE-2026-32201: Microsoft SharePoint Server Improper Input Validation Vulnerability
Exploited in the wild (CISA KEV). Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
CISA KEV · added 2026-04-14 CVSS 6.5 Medium EPSS 43.4% · p99
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- 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.
CISA’s summary
Microsoft SharePoint Server contains an improper input validation vulnerability that allows an unauthorized attacker to perform spoofing over a network.
Weakness type: CWE-20.
Product: Microsoft SharePoint Server · Assigned by: microsoft · Published: 2026-04-14
Affected and fixed versions
| Vendor | Product | Affected versions (per 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 scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoft | 3.1 | 6.5 Medium | 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 |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- 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.
Timeline
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CVE record published by microsoft
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Microsoft SharePoint Server Spoofing Vulnerability msrc.microsoft.com
- Listed in CISA KEV notes (msrc.microsoft.com) msrc.microsoft.com
Vulnerability records
- CVE.org record CVE-2026-32201 cve.org
- NVD entry CVE-2026-32201 nvd.nist.gov
Government
All exploited Microsoft vulnerabilities · Today’s Security Digest