CVE-2026-40357

highpriority · track · 1EPSS 0.023 · 83 %ileDEEUNLRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

2.29% (83rd) EPSS

CVSS 8.8 · high

Is it mine?

60 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-23

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedMicrosoft SharePoint Enterprise Server 2016msrc_csaf
16.0.5552.1002:Security Update:https://support.microsoft.com/help/5002868
https://support.microsoft.com/help/5002868
FixedMicrosoft SharePoint Server 2019msrc_csaf
16.0.10417.20128:Security Update:https://support.microsoft.com/help/5002870
https://support.microsoft.com/help/5002870
FixedMicrosoft SharePoint Server Subscription Editionmsrc_csaf
16.0.19725.20280:Security Update:https://support.microsoft.com/help/5002863
https://support.microsoft.com/help/5002863

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.8highAV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 2.8 · impact 5.9

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · NCSC-NL NL

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Microsoft Security Response Center US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-502USCWE-502USCWE-502USCWE-502US

affected products (60)

Products and version ranges known to be affected.

Microsoft 365 Appsall versionscert_bundDEcpe:/a:microsoft:365_apps:-
Microsoft Excel 2016all versionscert_bundDEcpe:/a:microsoft:excel:2016
Microsoft Excel for Androidall versionscert_bundDEcpe:/a:microsoft:excel:webapp:2010:sp2
Microsoft Office 2016all versionscert_bundDEcpe:/a:microsoft:office:2016
Microsoft Office 2019all versionscert_bundDEcpe:/a:microsoft:office:2019
Microsoft Office LTSC 2021all versionscert_bundDEcpe:/a:microsoft:office:ltsc_2021
Microsoft Office LTSC 2024all versionscert_bundDEcpe:/a:microsoft:office:ltsc_2024
Microsoft Office LTSC for Mac 2021all versionscert_bundDEcpe:/a:microsoft:office:ltsc_for_mac_2021
Microsoft Office LTSC for Mac 2024all versionscert_bundDEcpe:/a:microsoft:office:ltsc_for_mac_2024
Microsoft Office Online Serverall versionscert_bundDEcpe:/a:microsoft:office_online_server:-
Microsoft Office for Androidall versionscert_bundDEcpe:/a:microsoft:office:for_android
Microsoft Outlook for iOSall versionscert_bundDEcpe:/a:microsoft:outlook:for_ios
Microsoft PowerPoint for Androidall versionscert_bundDEcpe:/a:microsoft:powerpoint:for_android
Microsoft SharePoint Enterprise Server 2016all versionscert_bundDEcpe:/a:microsoft:sharepoint:enterprise_server_2016
Microsoft SharePoint Server 2019all versionscert_bundDEcpe:/a:microsoft:sharepoint_server_2019:-
Microsoft SharePoint Server Subscription Editionall versionscert_bundDEcpe:/a:microsoft:sharepoint:server_subscription_edition
Microsoft Teamsall versionscert_bundDEcpe:/a:microsoft:teams:-
Microsoft Teams for Androidall versionscert_bundDEcpe:/a:microsoft:teams:for_android
Microsoft Word 2016all versionscert_bundDEcpe:/a:microsoft:word:2016
Microsoft Microsoft SharePoint Enterprise Server 201616.0.0 → 16.0.5552.1002enisa_euvdEU

showing 20 of 60

advisories (3)

Vendor and ecosystem advisories describing this.

NCSC-2026-0144Kwetsbaarheden verholpen in Microsoft OfficeNL2026-05-12csaf · ncsc_nlNL
Microsoft heeft kwetsbaarheden verholpen in diverse Office producten.
WID-SEC-W-2026-1490Microsoft Office: Mehrere SchwachstellenDeutsch2026-05-12csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Excel, Microsoft Word, Microsoft Office, Microsoft Office Online Server, Microsoft SharePoint, Microsoft SharePoint Server 2019, Microsoft Outlook, Microsoft Teams, Microsoft 365 Apps und Microsoft PowerPoint ausnutzen, um erweiterte Berechtigungen – einschließlich Administratorrechte – zu erlangen, beliebigen Code im Kontext des Dienstes auszuführen, Spoofing-Angriffe durchzuführen, Daten zu manipulieren und vertrauliche Informationen offenzulegen.
msrc_CVE-2026-40357Microsoft SharePoint Server Remote Code Execution Vulnerability2026-05-12csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund ncsc_nl msrc_csaf NVD CVE.org MITRE

published 2026-05-12modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan