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Full vulnerability report · 2026
CVE-2026-70355High confidence

Microsoft SharePoint Server Elevation of Privilege Vulnerability

Microsoft · Microsoft SharePoint Server 2019

7.3HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2026-56602

No EUVD known-exploited evidence

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

What

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

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.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

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 Neutralization of Input During Web Page Generation ('Cross-site Scripting') → gain additional privileges
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
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-79 ↗

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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:L/UI:R/S:U/C:H/I:H/A:N

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.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.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.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.
NetworkPrivilege escalationCWE-79
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-56602Official EUVD mapping

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

Official EUVD record
BSI · German · WID-SEC-W-2026-2762Microsoft Office Produkte: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Office Produkte ausnutzen, um Dateien zu manipulieren, um seine Privilegien zu erhöhen, um Informationen offenzulegen, um einen Cross-Site Scripting Angriff durchzuführen, und um beliebigen Programmcode auszuführen.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-1004Multiples vulnérabilités dans les produits Microsoft

ulletin de sécurité Microsoft CVE-2026-69320 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70306 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70321 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70324 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70326 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70335 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70336 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70337 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70338 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70354 du 11 août 2026 Bulletin de sécurité Microsoft CVE-2026-70355 du 11 août 2026 Une gestion de version détaillée se trouve à la fin de ce document. Risques Atteinte à l'intégrité des données Atteinte à la confidentialité des données Contournement de la politique de sécurité Déni de service à distance Exécution de code arbitraire à distance Élévation de privilèges Systèmes affectés App Installer versions antérieures à 1.30.80 Microsoft Defender pour Endpoint pour Mac versions antérieures à 101.26042.0020 Microsoft Dynamics 365 (on-premises) version 9.1 antérieures à 9.1.0047.0006 Microsoft Dynamics 365 Business Central 2024 Release Wave 2 Microsoft Dynamics 365 Business Central 2026 Release Wave 1 version

Official advisory
CSIRT Italia · Italian · aggiornamenti-mensili-microsoft-23Aggiornamenti Mensili Microsoft

ice Windows Shell Windows Storage Windows Storage Port Driver Windows TCP/IP Windows Telephony Service Windows USB Driver Windows Universal Disk Format File System Driver (UDFS) Windows User Profile Service Windows Win32K Windows Wired AutoConfig Service Windows Work Folder Service Windows iSCSI Target Service Winlogon Azioni di mitigazione In linea con le dichiarazioni del vendor, si raccomanda di procedere all’aggiornamento dei prodotti impattati attraverso l’apposita funzione di Windows Update. CVE (420) Cerca: Tabella CVE CVE POC EXPLOITATION CVE-2026-72971 : apre una nuova finestra Presente - CVE-2026-71331 : apre una nuova finestra - - CVE-2026-70355 : apre una nuova finestra - - CVE-2026-70354 : apre una nuova finestra - - CVE-2026-70348 : apre una nuova finestra - - CVE-2026-70347 : apre una nuova finestra - - CVE-2026-70346 : apre una nuova finestra - - CVE-2026-70345 : apre una nuova finestra - - CVE-2026-70344 : apre una nuova finestra - - CVE-2026-70340 : apre una nuova finestra - - CVE-2026-70339 : apre una nuova finestra - - CVE-2026-70338 : apre una nuova finestra - - CVE-2026-70337 : apre una nuova finestra - - CVE-2026-70336 : apre una nuova finestra - - CVE-2026-70335 : apre una nuova finestra - - CVE-2026-70332 : apre una nuova finestra - - CVE-2026-70330 : apre una nuova fi

Official advisory
NCSC-NL · Dutch · NCSC-2026-0286Kwetsbaarheden verholpen in Microsoft Office

A cross-site scripting vulnerability in Microsoft Office SharePoint allows authorized attackers to elevate privileges over a network by improper input neutralization during web page generation.

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
16.0.0 < 16.0.10417.20198; 16.0.0 < 16.0.19725.20522
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 11 Aug 2026 · Last source change 10 Sept 2026, 15:49 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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-2026-56602
Product sourceCNA
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 →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-56602↗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-2026-70355 · cve.blacktree.nl