Microsoft Exchange Server Spoofing Flaws Tracked Across Multiple CVEs
Microsoft has published Security Update Guide entries for multiple Microsoft Exchange Server spoofing vulnerabilities, including CVE-2021-1730, CVE-2024-49040, and CVE-2025-64667. The references indicate a recurring class of flaws affecting Exchange Server in which an attacker could impersonate a trusted source or manipulate how identities or messages are presented, creating opportunities for phishing, fraud, or follow-on compromise in enterprise email environments.
The available advisories provide limited public technical detail, but the repeated publication of Exchange spoofing CVEs shows that Microsoft continues to track and remediate this attack surface through its update program. For defenders, the immediate implication is to review Exchange Server exposure, validate that relevant Microsoft security updates tied to these CVEs have been applied, and monitor mail infrastructure for signs of spoofed communications or abuse of trust relationships involving Exchange services.
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How this story unfolded
3 events from the most recent confirmed update back to the earliest known activity.
Microsoft publishes CVE-2025-64667 for Exchange Server spoofing
Microsoft listed CVE-2025-64667 as a Microsoft Exchange Server spoofing vulnerability in its Security Update Guide. No additional technical or impact details are provided in the reference content.
Microsoft publishes CVE-2024-49040 for Exchange Server spoofing
Microsoft published CVE-2024-49040 as a Microsoft Exchange Server spoofing vulnerability in its Security Update Guide and advisory materials. The vulnerability and advisory entries appear to refer to the same disclosure event.
Microsoft publishes CVE-2021-1730 for Exchange Server spoofing
Microsoft listed CVE-2021-1730 as a Microsoft Exchange Server spoofing vulnerability in its Security Update Guide. This indicates public disclosure of the vulnerability by Microsoft.
Sources
4 references tracked. Mallory keeps watching after this page renders.
CVE-2025-64667 - Security Update Guide - Microsoft - Microsoft Exchange Server Spoofing Vulnerability
msrc.microsoft.com
Open sourceCVE-2024-49040 - Security Update Guide - Microsoft - Microsoft Exchange Server Spoofing Vulnerability
msrc.microsoft.com
Open sourceCVE-2024-49040 - Security Update Guide - Microsoft - Microsoft Exchange Server Spoofing Vulnerability
msrc.microsoft.com
Open sourceCVE-2021-1730 - Security Update Guide - Microsoft - Microsoft Exchange Server Spoofing Vulnerability
msrc.microsoft.com
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