CVE-2026-21527

mediumpriority · track · 3OT risk · elevatedEPSS 0.083 · 95 %ileDEEUNLRUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

8.26% (95th) EPSS

CVSS 6.5 · medium

Is it mine?

46 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

User interface (ui) misrepresentation of critical information in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

remediations

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

A vendor fix is available.

FixedMicrosoft Exchange Server 2016 Cumulative Update 23msrc_csaf
15.01.2507.066:Security Update:https://support.microsoft.com/help/5074995
https://support.microsoft.com/help/5074995
FixedMicrosoft Exchange Server 2019 Cumulative Update 14msrc_csaf
15.02.1544.039:Security Update:https://support.microsoft.com/help/5074994
https://support.microsoft.com/help/5074994
FixedMicrosoft Exchange Server 2019 Cumulative Update 15msrc_csaf
15.02.1748.043:Security Update:https://support.microsoft.com/help/5074993
https://support.microsoft.com/help/5074993
FixedMicrosoft Exchange Server Subscription Edition RTMmsrc_csaf
15.02.2562.037:Security Update:https://support.microsoft.com/help/5074992
https://support.microsoft.com/help/5074992

cvss

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

6.5

010

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

v3.16.5mediumAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:Csecondary · ENISA EU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · secure@microsoft.com USexploitability 3.9 · impact 2.5

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:Csecondary · NCSC-NL NL

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/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: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-1286USCWE-1286USCWE-1286USCWE-345USCWE-345USCWE-451USCWE-451USCWE-451US

affected products (46)

Products and version ranges known to be affected.

Hitachi Storageall versionscert_bundDEcpe:/h:hitachi:storage:-
Microsoft Exchange Server 2016 Cumulative Update 23all versionscert_bundDEcpe:/a:microsoft:exchange:server_2016_cumulative_update_23
Microsoft Exchange Server 2019 Cumulative Update 14all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_14
Microsoft Exchange Server 2019 Cumulative Update 15all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_15
Microsoft Exchange Server Subscription Edition RTMall versionscert_bundDEcpe:/a:microsoft:exchange:server_subscription_edition_rtm
Microsoft Windows 10 Version 1607all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1607
Microsoft Windows 10 Version 1809all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1809
Microsoft Windows 10 Version 21H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_21h2
Microsoft Windows 10 Version 22H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_22h2
Microsoft Windows 11 Version 23H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_23h2
Microsoft Windows 11 Version 24H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_24h2
Microsoft Windows 11 Version 25H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_25h2
Microsoft Windows 11 Version 26H1all versionscert_bundDEcpe:/o:microsoft:windows_11:version_26h1
Microsoft Windows 11 version 26H1all versionscert_bundDE
Microsoft Windows App for Macall versionscert_bundDEcpe:/o:microsoft:windows:app_for_mac
Microsoft Windows Server 2012all versionscert_bundDEcpe:/o:microsoft:windows_server_2012:-
Microsoft Windows Server 2012 R2all versionscert_bundDEcpe:/o:microsoft:windows_server_2012_r2:-
Microsoft Windows Server 2016all versionscert_bundDEcpe:/o:microsoft:windows_server_2016:-
Microsoft Windows Server 2019all versionscert_bundDEcpe:/o:microsoft:windows_server_2019:-
Microsoft Windows Server 2022all versionscert_bundDEcpe:/o:microsoft:windows_server_2022:-

showing 20 of 46

advisories (4)

Vendor and ecosystem advisories describing this.

NCSC-2026-0054Kwetsbaarheid verholpen in Microsoft ExchangeNL2026-02-10csaf · ncsc_nlNL
Microsoft heeft een kwetsbaarheid verholpen in Exchange server.
WID-SEC-W-2026-0366Microsoft Exchange Server: Schwachstelle ermöglicht Darstellen falscher InformationenDeutsch2026-02-10csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Microsoft Exchange Server ausnutzen, um falsche Informationen darzustellen, wodurch begrenzte Informationen offengelegt oder Daten unautorisiert geändert werden können.
WID-SEC-W-2026-0369Microsoft Windows: Mehrere SchwachstellenDeutsch2026-02-10csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows-Produkten ausnutzen, um Administratorrechte zu erlangen, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Spoofing-Angriffe zu starten, Daten zu manipulieren, vertrauliche Informationen offenzulegen und einen Denial-of-Service-Zustand zu verursachen.
msrc_CVE-2026-21527Microsoft Exchange Server Spoofing Vulnerability2026-02-10csaf · 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 2026-02-10modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

scry

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