Actively Exploited — CISA KEV

CVE-2026-32201: Microsoft SharePoint Server Vulnerability

Severity: Medium | CVSS 3.1: 6.5 | Published: 2026-04-14 | KEV Added: 2026-04-14

What is CVE-2026-32201?

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

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-20 — Improper Input Validation. The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

Attack Vector Breakdown

  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality: Low
  • Integrity: Low
  • Availability: None

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction — making it straightforward to exploit at scale. The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

Exploitation Probability (EPSS): 7.9% chance of exploitation in the next 30 days (92th percentile). While the base probability may appear low, inclusion in CISA KEV confirms real-world exploitation is already occurring.

Is CVE-2026-32201 being exploited?

Yes. CVE-2026-32201 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-04-14. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-04-28.

How to fix CVE-2026-32201

Apply the latest security update via Windows Update, WSUS, or Microsoft Update Catalog. For enterprise environments, use SCCM/Intune for managed deployment. If the patch cannot be applied immediately, check the MSRC advisory for workarounds such as registry-based mitigations or disabling affected features. Check the Microsoft Security Response Center page for the specific patch or update. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting SharePoint Server or sharing the same weakness (CWE-20):

  • CVE-2025-32706 (High 7.8) [same vendor + same CWE] — Improper input validation in Windows Common Log File System Driver allows an…
  • CVE-2008-4250 (Critical 9.8) [same vendor] — The Server service in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003…
  • CVE-2009-1537 (High 8.8) [same vendor] — Unspecified vulnerability in the QuickTime Movie Parser Filter in quartz.dll…
  • CVE-2010-0249 (High 8.8) [same vendor] — Use-after-free vulnerability in Microsoft Internet Explorer 6, 6 SP1, 7, and 8…
  • CVE-2010-0806 (High 8.8) [same vendor] — Use-after-free vulnerability in the Peer Objects component (aka iepeers.dll)…

Frequently asked questions

Is CVE-2026-32201 critical?

CVE-2026-32201 has a CVSS 3.1 base score of 6.5 — Medium severity. Prioritize based on exposure and the active exploitation signal from the KEV listing.

Is CVE-2026-32201 being actively exploited?

Yes — CISA added CVE-2026-32201 to the Known Exploited Vulnerabilities catalog on 2026-04-14. Inclusion in KEV means CISA has confirmed in-the-wild exploitation.

How do I patch CVE-2026-32201?

Apply the security update from Microsoft for SharePoint Server. Federal agencies must remediate by 2026-04-28 under BOD 22-01. Refer to the Microsoft Security Response Center for the official patch.

What type of vulnerability is CVE-2026-32201?

CVE-2026-32201 is classified under CWE-20 (Improper Input Validation). The software does not properly validate input, allowing attackers to craft inputs that cause unexpected behavior, data corruption, or code execution.

What is the CVSS score for CVE-2026-32201?

CVE-2026-32201 has a CVSS 3.1 base score of 6.5, classifying it as Medium severity. The attack vector is Network, attack complexity is Low, and no privileges are required.