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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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3 events from the most recent confirmed update back to the earliest known activity.
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 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 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.
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Microsoft published security advisories for several spoofing vulnerabilities affecting **Microsoft Exchange Server** and **Microsoft OfficePlus**, identifying `CVE-2021-41350`, `CVE-2021-42305`, `CVE-2022-41078`, `CVE-2022-41079`, and `CVE-2025-55243`. The Exchange issues span multiple advisory releases and indicate a recurring class of flaws that could allow attackers to impersonate trusted senders, services, or content within enterprise messaging environments. The disclosures show Exchange Server as the primary affected platform, with four separate spoofing CVEs listed across 2021 and 2022, while a later advisory extends the same risk category to OfficePlus. Although the referenced notices provide limited public technical detail, the affected products are widely deployed in corporate communications workflows, making spoofing weaknesses operationally significant for phishing, fraud, and trust-boundary bypass scenarios until patches are applied.
Jul 12, 2026
Microsoft disclosed multiple vulnerabilities in on-premises **Exchange Server**, including **CVE-2021-31207** (security feature bypass), **CVE-2021-31209** (spoofing), and **CVE-2022-41040** (elevation of privilege). The issues affected Exchange deployments rather than **Exchange Online**, extending a pattern of high-impact weaknesses in the mail platform that could undermine trust boundaries, enable impersonation, and weaken built-in protections. Among them, **CVE-2022-41040** was rated **Critical** with a **CVSS 3.1 score of 8.8**, and Microsoft said exploitation had been detected in the wild before public disclosure. The flaw required an authenticated attacker with low privileges and no user interaction, and successful exploitation could allow the attacker to run **PowerShell** as **`SYSTEM`**. Microsoft later released security updates and directed Exchange Server customers to apply mitigations and patches for the reported zero-day issues.
Jun 29, 2026
Microsoft published security advisories for several **Microsoft Exchange Server remote code execution** vulnerabilities, including `CVE-2021-26427`, `CVE-2022-21969`, `CVE-2022-23277`, and `CVE-2023-36778`. The flaws affect on-premises Exchange Server deployments and were addressed through Microsoft's Security Update Guide, indicating a recurring pattern of high-impact code-execution risk in a core enterprise messaging platform. The advisories show Microsoft issuing fixes over multiple release cycles for distinct Exchange Server RCE bugs rather than a single isolated defect. For defenders, the immediate implication is to verify that all supported Exchange Server instances have the relevant cumulative and security updates applied, because unpatched mail servers remain a high-value target due to their internet exposure, privileged position in enterprise environments, and history of exploitation by threat actors.
Jul 12, 2026