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Full vulnerability report · 2025
CVE-2025-53770High confidence

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Microsoft · SharePoint

9.8CriticalCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2025-07-21 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • CISA confirms exploitation in the wild.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 100.00% 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 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-2025-23309

EU known exploited

Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network. Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild. Microsoft is preparing and fully testing a comprehensive update to address this vulnerability. In the meantime, please make sure that the mitigation provided in this CVE documentation is in place so that you are protected from exploitation.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 20 Jul 2025. Evidence sources: cisa_kev, eukev_kev.
ENISA score
9.8 · CVSS 3.1
Advisory evidence
3 linked advisory records
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2025-07-21 as the remediation due date.

Patch available
01

What, why and how

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.

What

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

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 2025-07-20. Known ransomware campaign use is recorded.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Deserialization of Untrusted Data → execute code or commands in the affected security context
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-502 ↗

CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

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:H/I:H/A:H/E:F/RL:W/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.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkUnauthenticatedRemote code executionCWE-502CISA KEVPublic exploit reference
A

Official authority intelligence

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

ENISA EUVD · EUVD-2025-23309Known-exploited evidence recorded

Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network. Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild. Microsoft is preparing and fully testing a comprehensive update to address this vulnerability. In the meantime, please make sure that the mitigation provided in this CVE documentation is in place so that you are protected from exploitation.

Official EUVD record ↗
BSI · German · WID-SEC-2025-1598Microsoft SharePoint (On-premises): Mehrere Schwachstellen

Ein entfernter anonymer oder authentifizierter Angreifer kann mehrere Schwachstellen in Microsoft SharePoint Server 2019, Microsoft SharePoint Subscription Edition und Microsoft SharePoint Server 2016 ausnutzen, um beliebigen Code auszuführen und Spoofing-Angriffe durchzuführen.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV25-433Microsoft SharePoint security advisory (AV25-433) – Update 1

On July 19, 2025, Microsoft published a security advisory to address vulnerabilities in multiple products. Included were critical updates for the following products: Microsoft states that for SharePoint 2016 and 2019 "Both the server and language pack updates should be installed".

Official advisory ↗
Canadian Centre for Cyber Security · English · AL25-009AL25-009 - Vulnerability impacting Microsoft SharePoint Server (CVE-2025-53770, CVE-2025-49704, CVE-2025-53771, CVE-2025-49706 and CVE-2025-49712) – Update 4

An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20250724Security Bulletin 24 Jul 2025 [701KB]

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 24 Jul 2025 [701KB], published on 24 July 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0611Multiples vulnérabilités dans les produits Microsoft

De multiples vulnérabilités ont été découvertes dans les produits Microsoft. Elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un contournement de la politique de sécurité. Microsoft indique que la vulnérabilité CVE-2025-53770 est activement exploitée.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-009668マイクロソフトの Microsoft SharePoint Server および SharePoint Enterprise Server におけるリモートでコードを実行される脆弱性

マイクロソフトの Microsoft SharePoint Server および SharePoint Enterprise Server には、リモートでコードを実行される脆弱性が存在します。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6556MS 8월 보안 위협에 따른 정기 보안 업데이트 권고

E-2025-53783 | Microsoft Teams 원격 코드 실행 취약성 | | Azure Virtual Machines | CVE-2025-53781 | Azure Virtual Machines Information Disclosure Vulnerability | | Windows Kerberos | CVE-2025-53779 | Windows Kerberos 권한 상승 취약성 | | Windows NTLM | CVE-2025-53778 | Windows NTLM 권한 상승 취약성 | | Microsoft 365 Copilot's Business Chat | CVE-2025-53774 | Microsoft 365 Copilot BizChat 정보 공개 취약성 | | GitHub Copilot and Visual Studio | CVE-2025-53773 | GitHub Copilot 및 Visual Studio 원격 코드 실행 취약성 | | Web Deploy | CVE-2025-53772 | 웹 배포 원격 코드 실행 취약성 | | Microsoft Office SharePoint | CVE-2025-53771 | Microsoft SharePoint Server 스푸핑 취약성 | | Microsoft Office SharePoint | CVE-2025-53770 | Microsoft SharePoint Server Remote Code Execution Vulnerability | | Windows Security App | CVE-2025-53769 | Windows 보안 앱 스푸핑 취약성 | | Azure OpenAI | CVE-2025-53767 | Azure OpenAI 권한 상승 취약성 | | Windows GDI+ | CVE-2025-53766 | GDI+ 원격 코드 실행 취약성 | | Azure Stack | CVE-2025-53765 | Azure Stack Hub 정보 공개 취약성 | | Microsoft Purview | CVE-2025-53762 | Microsoft Purview 권한 상승 취약성 | | Microsoft Office PowerPoint | CVE-2025-53761 | Microsoft PowerPoint 원격 코드 실행 취약성 | | Microsoft Office SharePoint | CVE-2025-53760 | Microsoft SharePoint 권한 상승 취약성 | | Microsoft Office Excel | CVE-2025-53759 | Microsoft Excel 원격 코드 실행 취약성 | | Microsoft Office Excel | CVE-

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6540美 CISA 발표 주요 Exploit 정보공유(Update. 2025-07-22)

, SharePoint Server 2013 and earlier versions are end-of-life and should be discontinued if still in use. For supported versions, please follow the mitigations according to CISA and vendor instructions. Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available. | 2025-07-23 | | CVE-2025-49704 | Microsoft | Microsoft SharePoint Code Injection Vulnerability | 2025-07-22 | Microsoft SharePoint contains a code injection vulnerability that could allow an authorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-49706. The update for CVE-2025-53770 includes more robust protections than the update for CVE-2025-49704. | CISA recommends disconnecting public-facing versions of SharePoint Server that have reached their end-of-life (EOL) or end-of-service (EOS). For example, SharePoint Server 2013 and earlier versions are end-of-life and should be discontinued if still in use. For supported versions, please follow the mitigations according to CISA and vendor instructions. Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available. | 2025-07-23 | | CVE-2025-54309 | CrushFTP | CrushFTP Unprotected Alternate Channel Vulnerab

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6537Microsoft 제품 보안 업데이트 권고

Microsoft SharePoint Server에서 신뢰할 수 없는 데이터를 역직렬화하여 발생하는 원격 코드 실행 취약점(CVE-2025-53770) [1][3]

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6533美 CISA 발표 주요 Exploit 정보공유(Update. 2025-07-20)

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network.

Official advisory ↗
NCSC-NL · Dutch · NCSC-2025-0233Zeroday-kwetsbaarheden ontdekt in Microsoft SharePoint Server

De zeroday-kwetsbaarheden, met kenmerk CVE-2025-53770 en CVE-2025-53771, stellen een kwaadwillende in staat om willekeurige code uit te voeren op SharePoint Server-systemen. Kwaadwillenden kunnen op deze manier toegang krijgen tot gevoelige gegevens of verdere aanvallen op het netwerk van het slachtoffer uitvoeren. Het NCSC heeft signalen ontvangen dat de kwetsbaarheden actief worden misbruikt. Naast Microsoft heeft onder andere beveiligingsbedrijf Eye Security hier op hun website over bericht. Tevens is proof-of-conceptcode (PoC) gepubliceerd waarmee de kwetsbaarheid met kenmerk CVE-2025-53770 kan worden misbruikt. Het NCSC heeft de werking van dit PoC niet geverifieerd, maar acht het aannemelijk dat het PoC functioneel is. Het is daarom de verwachting dat het aantal pogingen tot misbruik verder toeneemt. De kwetsbaarheden zijn varianten van de eerder actief misbruikte kwetsbaarheden CVE-2025-49704 en CVE-2025-49706. Voor deze kwetsbaarheden heeft het NCSC beveiligingsadvies NCSC-2025-0215 uitgebracht, waarvoor op 19 juli een update is verschenen met kans en inschaling HIGH/HIGH.

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.
04

Evidence and provenance

Published 20 Jul 2025 · Last source change 4 Aug 2026, 03:55 UTC · CWE-502 · Deserialization of Untrusted Data

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-2025-23309
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. Affected versionsThe structured affected or fixed version information changed.
    Before
    16.0.0 < 16.0.5513.1001; 16.0.0 < 16.0.10417.20037; 16.0.0 < 16.0.18526.20508 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Microsoft SharePoint Enterprise Server 2016: 16.0.0 < 16.0.5513.1001; Microsoft SharePoint Server 2019: 16.0.0 < 16.0.10417.20037; Microsoft SharePoint Server Subscription Edition: 16.0.0 < 16.0.18526.20508 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Mitigation reference recorded
ENISA EUVD · EUVD-2025-23309↗CISA KEV record↗CVE authority or vendor reference↗Mitigation reference↗Public exploit reference↗Public exploit 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-2025-53770 · cve.blacktree.nl