【Vulnerability Alert】Microsoft Exchange Server Contains a High-Risk Security Vulnerability (CVE-2026-62911). Please Confirm and Apply Patches as Soon as Possible

publish date : 2026-09-11 update date : 2026-09-11

Source: Ministry of education information & communication security contingency platform

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Publication Number TACERT-ANA-2026090803095050 Publication Time 2026-09-08 15:33:51
Incident Type ANA-Vulnerability Alert Discovery Time 2026-09-08 15:33:51
Impact Level Medium  
[Subject]
【Vulnerability Alert】Microsoft Exchange Server Contains a High-Risk Security Vulnerability (CVE-2026-62911). Please Confirm and Apply Patches as Soon as Possible
[Content]

Forwarded from the National Institute of Cyber Security Cybersecurity Alert NISAC-200-202609-00000007

Researchers discovered that Microsoft Exchange Server contains an Authentication Bypass vulnerability (CVE-2026-62911). An authenticated remote attacker may induce a user to interact with specially crafted content in order to intercept and replay authentication credentials, thereby bypassing the server's authentication mechanism, escalating privileges, and gaining access to user mailboxes on the server. Please confirm and apply patches as soon as possible.

Information Sharing Level: WHITE (the intelligence content is information that may be publicly disclosed)

[Affected Platform]

Microsoft Exchange Server 2016 Cumulative Update 23 versions prior to 15.01.2507.072

[Recommended Actions]

The official vendor has released a patch for the vulnerability. Please update to the following versions:

Microsoft Exchange Server 2016 Cumulative Update 23 version 15.01.2507.072 or later

Microsoft Exchange Server 2019 Cumulative Update 14 version 15.02.1544.044 or later

Microsoft Exchange Server 2019 Cumulative Update 15 version 15.02.1748.049 or later

Microsoft Exchange Server Subscription Edition RTM version 15.02.2562.046 or later

For detailed information, please refer to the official advisory. The URL is as follows: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62911

[Reference]

1. https://nvd.nist.gov/vuln/detail/CVE-2026-62911
2. https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62911

(This notification is for informational purposes only and does not constitute a cybersecurity incident).
If you have questions or suggestions regarding this notification, please feel free to contact us.
Ministry of education information & communication security contingency platform
Website: https://info.cert.tanet.edu.tw/
Phone: +886-7-5250211
Internet Phone: 98400000
E-Mail: service@cert.tanet.edu.tw
Organizer: Computer Center