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Exploited

CVE-2026-32201

Microsoft SharePoint Server · Collaboration, telephony and video conferencing

Microsoft SharePoint Server Improper Input Validation Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on April 14, 2026.

Affected product: Microsoft SharePoint Server (category Collaboration, telephony and video conferencing, indicative classification). Name in CISA’s catalog: Microsoft SharePoint Server.

Microsoft component: SharePoint (Messaging and collaboration).

What should I do?

Apply the patches or mitigations from Microsoft; if none are available, stop using the product. For cloud services, follow the guidance from Microsoft.

Deadline set by CISA for US federal agencies: 14 days (due April 28, 2026). It only binds those agencies, but it is a useful measure of urgency.

Original text of the required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Timeline

  1. Vulnerability published Publication date (NVD)
  2. Exploitation confirmed Added to CISA’s KEV catalog
  3. CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed
Yes, on April 14, 2026 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware
No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise
Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action
Apply the patches or mitigations from Microsoft; if none are available, stop using the product. For cloud services, follow the guidance from Microsoft. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline
April 28, 2026, 14 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Microsoft patch
Not available Source: Security Update Guide, collected September 29, 2026 at 14:57 UTC
Vulnerability published
April 14, 2026 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA
Microsoft SharePoint Server Filed by this site under “Collaboration, telephony and video conferencing” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

6.5 / 10 CVSS severity: medium

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

Description

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

Official description from the NVD, collected Sep 29, 2026. CVE® description © The MITRE Corporation.

Microsoft SharePoint Server contains an improper input validation vulnerability that allows an unauthorized attacker to perform spoofing over a network.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page