CVE-2025-64666

highpriority · track · 30EPSS 0.010 · 63 %ileDEEUNLRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.02% (63rd) EPSS

CVSS 7.5 · high

Is it mine?

46 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-22

Improper input validation in Microsoft Exchange Server allows an authorized attacker to elevate privileges 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
15.01.2507.063:Security Update:https://support.microsoft.com/help/5071873
https://support.microsoft.com/help/5071873
FixedMicrosoft Exchange Server 2019 Cumulative Update 14msrc_csaf
15.02.1544.037:Security Update:https://support.microsoft.com/help/5071874
https://support.microsoft.com/help/5071874
FixedMicrosoft Exchange Server 2019 Cumulative Update 15msrc_csaf
15.02.1748.042:Security Update:https://support.microsoft.com/help/5071875
https://support.microsoft.com/help/5071875
FixedMicrosoft Exchange Server Subscription Edition RTMmsrc_csaf
15.02.2562.035:Security Update:https://support.microsoft.com/help/5071876
https://support.microsoft.com/help/5071876

cvss

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

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.6 · impact 5.9

v3.17.5highAV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 1.6 · impact 5.9

v3.16.9mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17.5highCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · NCSC-NL NL

v3.17.5highCVSS:3.1/AV:N/AC:H/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-20USCWE-20USCWE-20USCWE-20US

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 10all versionscert_bundDEcpe:/o:microsoft:windows_10:-
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 22H2all versionscert_bundDEcpe:/o:microsoft:windows_11: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 Windows Terminalall versionscert_bundDEcpe:/o:microsoft:windows_11:windows_terminal
Microsoft Windows Server 2008 R2 SP1all versionscert_bundDEcpe:/o:microsoft:windows_server:2008_r2_sp1
Microsoft Windows Server 2008 SP2all versionscert_bundDEcpe:/o:microsoft:windows_server:2008_sp2
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:-

showing 20 of 46

advisories (4)

Vendor and ecosystem advisories describing this.

NCSC-2025-0385Kwetsbaarheden verholpen in Microsoft ExchangeNL2025-12-09csaf · ncsc_nlNL
Microsoft heeft kwetsbaarheden verholpen in Exchange.
WID-SEC-W-2025-2780Microsoft Exchange Server: Mehrere SchwachstellenDeutsch2025-12-09csaf · cert_bundDE
Ein entfernter, authentisierter oder anonymer Angreifer kann mehrere Schwachstellen in Microsoft Exchange Server 2016, Microsoft Exchange Server 2019 und Microsoft Exchange ausnutzen, um Administratorrechte zu erlangen und Spoofing-Angriffe durchzuführen.
WID-SEC-W-2025-2781Microsoft Windows: Mehrere SchwachstellenDeutsch2025-12-09csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows und Microsoft Windows Server ausnutzen, um beliebigen Programmcode auszuführen, Rechte zu eskalieren, vertrauliche Informationen auszulesen oder den Host zum Absturz zu bringen.
msrc_CVE-2025-64666Microsoft Exchange Server Elevation of Privilege Vulnerability2025-12-09csaf · 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 2025-12-09modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

scry

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