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Full vulnerability report · 2026
CVE-2026-32201High confidence

Microsoft SharePoint Server Improper Input Validation Vulnerability

Microsoft · SharePoint Server

6.5MediumCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2026-04-28 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Critical, raised 2 bands.upgradedsince 14 Apr 2026

Evidence used

  • CISA confirms exploitation in the wild.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 43.38% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Microsoft SharePoint Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-22587

CISA KEV mirrored by ENISA

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

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 14 Apr 2026. Evidence sources: cisa_kev.
ENISA score
6.5 · CVSS 3.1
Advisory evidence
2 linked advisory records
Explicit mitigation evidence

Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.

  • csaf_ncscnl · NCSC-2026-0116Kwetsbaarheden verholpen in Microsoft Office
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2026-04-28 as the remediation due date.

Patch available
01

What, why and how

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

What

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

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-04-14.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
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

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-20CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-22587Known-exploited evidence recorded

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

Official EUVD record ↗
BSI · German · WID-SEC-2026-1102Microsoft Office: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Excel, Microsoft PowerPoint, Microsoft Office, Microsoft Office Online Server, Microsoft SharePoint, Microsoft SharePoint Server 2019 und Microsoft 365 Apps ausnutzen, um beliebigen Programmcode auszuführen, Spoofing-Angriffe durchzuführen, Daten zu manipulieren und vertrauliche Informationen offenzulegen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV26-352Microsoft security advisory – April 2026 monthly rollup (AV26-352) - Update 3

On April 14, 2026, Microsoft published security advisories to address vulnerabilities in multiple products. Included were critical updates for the following products: Microsoft has received reports that CVE-2026-32201 has been exploited.

Official advisory ↗
CERT-EU · English · CERT-EU-2026-009Critical Vulnerabilities in Microsoft SharePoint

[UPDATED] On 14 July 2026, Microsoft released security updates addressing critical remote code execution (RCE) vulnerabilities in Microsoft SharePoint Server [1]. On 20 July 2026, WatchTowr identified a proof-of-concept exploit code and subsequently observed active exploitation of CVE-2026-50522 [2], a vulnerability part of an ongoing series of actively exploited flaws [3] affecting on-premise SharePoint Server instances, including CVE-2026-32201, CVE-2026-45659, CVE-2026-56164, and CVE-2026-58644. CERT-EU strongly recommends updating affected servers immediately, rotating credentials for any assets that may have been exposed to the internet, and conducting a compromise assessment.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260415Security Bulletin 15 April 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 15 April 2026, published on 15 April 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0445Multiples vulnérabilités dans les produits Microsoft

De multiples vulnérabilités ont été découvertes dans les produits Microsoft. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un déni de service à distance. Microsoft indique que la vulnérabilité CVE-2026-32201 est activement exploitée.

Official advisory ↗
CSIRT Italia · Italian · aggiornamenti-mensili-microsoft-19Aggiornamenti Mensili Microsoft

Aggiornamenti Mensili Microsoft Aggiornamenti Mensili Microsoft Alert AL02/260415/CSIRT-ITA Condividi Facebook Twitter LinkedIn Whatsapp Sintesi Microsoft ha rilasciato gli aggiornamenti di sicurezza mensili che risolvono un totale di 165 nuove vulnerabilità, di cui due di tipo 0-day. Tipologia Denial of Service Elevation of Privilege Information Disclosure Remote Code Execution Security Feature Bypass Spoofing Tampering Descrizione e potenziali impatti Nel dettaglio le vulnerabilità sfruttate attivamente o per le quali risulta disponibile in rete anche un “proof of concept”, riguardano: Microsoft SharePoint Server : identificata tramite la CVE-2026-32201, di tipo “ Spoofing ” e con score CVSS v3.1 pari a 6.5, interessa le istanze Microsoft SharePoint Server ed è causata da un’inadeguata validazione dell’input ( Improper Input Validation ). Nel dettaglio, un attaccante potrebbe sfruttare tale vulnerabilità per impersonare un’entità legittima sui sistemi target. Microsoft Defender Antimalware Platform: questo CSIRT ha analizzato e testato la CVE-2026-33825, nota con il nome di “BlueHammer”, di tipo “ Elevation of Privilege ” e con score CVSS v3.1 pari a 7.8, che interessa Microsoft Defender Antimalware Platform. In dettaglio, è stato verificato che la vulnerabilità è riconducibile a una condiz

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-017391マイクロソフトのMicrosoft SharePoint Serverにおける入力確認に関する脆弱性

Microsoft Office SharePointの不適切な入力検証により、不正な攻撃者がネットワーク上でなりすましを行うことが可能となります。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6760MS 4월 보안 위협에 따른 정기 보안 업데이트 권고

Agent Elevation of Privilege Vulnerability | | Windows 패널 | CVE-2026-32195 | Windows Kernel Elevation of Privilege Vulnerability | | Windows 관리 센터 | CVE-2026-32196 | Windows Admin Center Spoofing Vulnerability | | 마이크로소프트 오피스 엑셀 | CVE-2026-32197 | Microsoft Office Excel Remote Code Execution Vulnerability | | 마이크로소프트 오피스 엑셀 | CVE-2026-32198 | Microsoft Office Excel Remote Code Execution Vulnerability | | 마이크로소프트 오피스 엑셀 | CVE-2026-32199 | Microsoft Office Excel Remote Code Execution Vulnerability | | Microsoft Office PowerPoint | CVE-2026-32200 | Microsoft Office PowerPoint Remote Code Execution Vulnerability | | Microsoft Office SharePoint | CVE-2026-32201 | Microsoft Office SharePoint Spoofing Vulnerability | | 윈도우 셸 | CVE-2026-32202 | Windows Shell Spoofing Vulnerability | | .NET 및 Visual Studio | CVE-2026-32203 | .NET and Visual Studio Denial of Service Vulnerability | | 유니버설 플러그 앤 플레이(upnp.dll) | CVE-2026-32212 | Universal Plug and Play (upnp.dll) Information Disclosure Vulnerability | | 유니버설 플러그 앤 플레이(upnp.dll) | CVE-2026-32214 | Universal Plug and Play (upnp.dll) Information Disclosure Vulnerability | | Windows 패널 | CVE-2026-32215 | Windows Kernel Information Disclosure Vulnerability | | Windows 드라이버 복구 | CVE-2026-32216 | Windows Redirected Drive Buffering Denial of Service Vulnerability

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6759美 CISA 발표 주요 Exploit 정보공유(Update. 2026-04-14)

Microsoft SharePoint Server Improper Input Validation Vulnerability

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0116Kwetsbaarheden verholpen in Microsoft Office

Een kwaadwillende kan de kwetsbaarheden misbruiken om beveiligingsmaatregelen te omzeilen, zoch voor te doen als andere gebruiker en zich zo verhoogde rechten toe te kennen en toegang te krijgen tot gevoelige gegevens. Voor succesvol misbruik moet de kwaadwillende het slachtoffer misleiden en malafide bestand te openen of link te volgen. ``` Microsoft Office PowerPoint: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2026-32200 | 7,80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Microsoft Office Word: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2026-33095 | 7,80 | Uitvoeren van willekeurige code | | CVE-2026-33822 | 6,10 | Toegang tot gevoelige gegevens | | CVE-2026-23657 | 7,80 | Uitvoeren van willekeurige code | | CVE-2026-33114 | 8,40 | Uitvoeren van willekeurige code | | CVE-2026-33115 | 8,40 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Microsoft Office: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2026-32190 | 8,40 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Microsoft Office SharePoint: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2026-20945 | 4,60 | Voordoen als andere gebruiker | | CVE-2026-32201 | 6,50 | Voordoen als andere gebruiker | |----------------|------|-------------------------------------| Microsoft Office Excel: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2026-32188 | 7,10 | Toegang tot gevoelige gegevens | | CVE-2026-32189 | 7,80 | Uitvoeren van willekeurige code | | CVE-2026-32197 | 7,80 | Uitvoeren van willekeurige code | | CVE-2026-32198 | 7,80 | Uitvoeren van willekeurige code | | CVE-2026-32199 | 7,80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| ```

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
Official vendor articles3 stored documents

Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.

04

Evidence and provenance

Published 14 Apr 2026 · Last source change 15 Oct 2026, 15:53 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-22587
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352.
    Before
    remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352 · vendor advisory: msrc.microsoft.com/CVE-2026-32201
    After
    vendor advisory: msrc.microsoft.com/CVE-2026-32201
    secure@microsoft.com ↗
  2. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    secure@microsoft.com ↗
  3. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352.
    Before
    remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352 · vendor advisory: msrc.microsoft.com/CVE-2026-32201
    After
    vendor advisory: msrc.microsoft.com/CVE-2026-32201
    secure@microsoft.com ↗
  4. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    secure@microsoft.com ↗
  5. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352.
    Before
    remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352 · vendor advisory: msrc.microsoft.com/CVE-2026-32201
    After
    vendor advisory: msrc.microsoft.com/CVE-2026-32201
    secure@microsoft.com ↗
  6. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    secure@microsoft.com ↗
  7. BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.
    Before
    no BlackTree article
    After
    1 BlackTree article
    BlackTree editorial ↗
  8. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352.
    Before
    remediation: cyber.gc.ca/microsoft-security-advisory-april-2026-monthly-rollup-av26-352 · vendor advisory: msrc.microsoft.com/CVE-2026-32201
    After
    vendor advisory: msrc.microsoft.com/CVE-2026-32201
    secure@microsoft.com ↗
  9. Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
    Before
    Mitigation available
    After
    Awaiting fix
    secure@microsoft.com ↗
  10. Affected versionsThe structured affected or fixed version information changed.
    Before
    16.0.0 < 16.0.5548.1003; 16.0.0 < 16.0.10417.20114; 16.0.0 < 16.0.19725.20210 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Microsoft SharePoint Enterprise Server 2016: 16.0.0 < 16.0.5548.1003; Microsoft SharePoint Server 2019: 16.0.0 < 16.0.10417.20114; Microsoft SharePoint Server Subscription Edition: 16.0.0 < 16.0.19725.20210 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  11. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Canadian Centre for Cyber Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Remediation guidance recorded
ENISA EUVD · EUVD-2026-22587↗Canadian Centre for Cyber Security remediation guidance↗CISA KEV record↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-32201 · cve.blacktree.nl