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Microsoft disclosed and patched CVE-2021-31196, a remote code execution vulnerability in Microsoft Exchange Server. The company rated the flaw Important and assigned it a CVSS 3.0 score of 7.2, with the vector AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, indicating the issue is reachable over the network, requires no user interaction, and could lead to high impact across confidentiality, integrity, and availability if successfully exploited.
Microsoft said the vulnerability required high privileges, assessed exploitation as less likely, and reported that exploit code was unproven and that the flaw was not publicly disclosed or actively exploited at the time of publication. An official security update was made available through the Microsoft Security Response Center, and Microsoft credited Orange Tsai of DEVCORE with reporting the issue.
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1 event from the most recent confirmed update back to the earliest known activity.
Microsoft published advisory CVE-2021-31196 for a remote code execution vulnerability in Microsoft Exchange Server, rated Important with a CVSS 7.2 score. The company stated a fix was available, said the issue was not publicly disclosed or exploited at the time of publication, and credited Orange Tsai of DEVCORE for reporting it.
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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
Microsoft has disclosed multiple **elevation of privilege** vulnerabilities affecting **Microsoft Exchange Server**, including `CVE-2021-34470`, `CVE-2021-41348`, `CVE-2022-41123`, and `CVE-2025-64666`, indicating a recurring security issue in the on-premises mail platform across several release cycles. The advisories show Exchange continued to receive fixes for privilege-escalation weaknesses over multiple years, with Microsoft publishing separate Security Update Guide entries as new flaws were identified. Among the listed issues, Microsoft provided the most detail for `CVE-2021-34470`, rating it **Important** with a **CVSS 3.0 score of 8.0** and describing it as requiring access from a logically adjacent network. Microsoft said the flaw required a **schema change** and was fixed for **Exchange Server 2019** and **Exchange Server 2016** in cumulative updates released on June 29, 2021; at initial publication, the company said it was **not publicly disclosed**, **not exploited**, and **less likely to be exploited**. A separate Microsoft advisory in the same reference set, `CVE-2026-26128`, affects the **Windows SMB Server** rather than Exchange and also involves elevation of privilege.
Jun 29, 2026
Microsoft disclosed and patched several **remote code execution** vulnerabilities affecting **Exchange Server** and **SharePoint Server**, including Exchange flaws tracked as `CVE-2023-21706`, `CVE-2023-28310`, and `CVE-2023-36439`, alongside SharePoint issues `CVE-2026-33110`, `CVE-2026-33112`, and `CVE-2026-40368`. The SharePoint vulnerabilities were tied to **deserialization of untrusted data** and were rated **Important**, with CVSS scores of **8.8** for `CVE-2026-33110` and `CVE-2026-33112`, and **8.0** for `CVE-2026-40368`. Microsoft said `CVE-2026-33110` could let an authenticated attacker with at least **Site Member** permissions execute code remotely on a vulnerable SharePoint Server, while `CVE-2026-33112` required at least **Site Owner** privileges to inject and run arbitrary code. For `CVE-2026-40368`, exploitation involved a client connecting to a malicious server, potentially leading to code execution on the client. Microsoft reported that the SharePoint flaws were **not publicly disclosed** and **not exploited in the wild** at publication, assessed exploitation as less likely, and released fixes, including a shared KB update for **SharePoint Server 2016** and **SharePoint Enterprise Server 2016**.
Jun 29, 2026