Cyber Resilience

CVE-2025-64667

Microsoft Exchange Server 2016 … 2019

Published
09 December 2025
Modified
15 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0084 54th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-64667 is a medium-severity User Interface (UI) Misrepresentation of Critical Information (CWE-451) vulnerability in Microsoft Exchange Server. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Masquerading (T1036); ranked in the top 46% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-15 (Information Output Filtering) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

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

CWE(s)
CWE-451

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1036 Masquerading Stealth
Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools.
attack.mitre.org →
Why these techniques?

UI misrepresentation of critical information enables masquerading (T1036) to facilitate spoofing attacks over a network.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-21527Same product: Microsoft Exchange Server
CVE-2025-53782Same product: Microsoft Exchange Server
CVE-2025-25007Same product: Microsoft Exchange Server
CVE-2025-25006Same product: Microsoft Exchange Server
CVE-2026-45504Same product: Microsoft Exchange Server
CVE-2025-33051Same product: Microsoft Exchange Server
CVE-2026-45500Same product: Microsoft Exchange Server
CVE-2026-55009Same product: Microsoft Exchange Server
CVE-2026-55005Same product: Microsoft Exchange Server
CVE-2025-59248Same product: Microsoft Exchange Server

Affected Assets

microsoft
exchange server
2016, 2019
microsoft
exchange server subscription edition
≤ 15.02.2562.035

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-15 Information Output Filtering
  • SI-10 Information Input Validation
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SI-15 Information Output Filtering good match
prevent

Directly filters and sanitizes information output to block UI misrepresentation that enables spoofing.

SI-10 Information Input Validation partial match
prevent

Validates input data to Exchange to stop malformed content from producing misleading UI elements.

AC-4 Information Flow Enforcement partial match
prevent

Enforces information flow rules so that identity and content attributes cannot be misrepresented to users.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly address design and implementation of accurate, non-spoofable UI elements.

PR.AT-01 partial match
prevents

User awareness training helps people recognize and avoid harm from UI misrepresentation such as phishing, but does not prevent the flaw itself.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing can detect UI misrepresentation vulnerabilities before deployment.

A.6.3 Information security awareness, education and training partial match
prevents

Security awareness training can teach users to recognize UI misrepresentation and phishing attempts.

A.8.23 Web filtering partial match
mitigates

Web filtering can block known phishing sites that exploit UI misrepresentation.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes UI/UX security requirements that can prevent misrepresentation of critical information.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate proper display and validation of critical information in the UI.

A.8.28 Secure coding partial match
prevents

Secure coding practices can prevent UI flaws that obscure or spoof critical information.

References