We require the Exchange2019-KB5129957-x64-en.exe patch to mitigate the ongoing attack attempts targeting the server.

Question

We require the Exchange2019-KB5129957-x64-en.exe patch to mitigate the ongoing attack attempts targeting the server.

Enrique Gustavo Dutra 0 MVP

We have a scenario involving a server that is currently under attack. The server is running Microsoft Windows Server 2019 (64-bit), Build 17763, and we need the Microsoft-released patch Exchange2019-KB5129957-x64-en.exe in an effort to mitigate the ongoing attack attempts affecting the server.

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Answer 1

Nam-D 4,080 Microsoft External Staff Moderator

Hello @Enrique Gustavo Dutra

Microsoft has published Description of version 2 of the security update for Microsoft Exchange Server 2019 CU14 October 2, 2026 (KB5129957), which includes the package Exchange2019-KB5129957-x64-en.exe. This update addresses multiple security vulnerabilities in Exchange Server 2019.

If your organization has already purchased the ESU program and you require information on how to access the latest security updates, Microsoft advises contacting them directly at:

User's image

You can find the information in this Microsoft article for KB5129957 here:

Exchange Server 2019 CU14 Security Update (KB5129957)

Additionally, please ensure that your Exchange Server is running the supported cumulative update level required for this security update before attempting installation.

I hope this information is helpful. Please let me know if you need assistance verifying your current Exchange build version or cumulative update level.

Enrique Gustavo Dutra 0 Reputation points MVP

2026-10-07T15:35:22.6033333+00:00

Thank you very much, Nam. It's for a company's server and they don't have the ESU, and on top of that, it expires now in October, it doesn't make sense to pay for it since it expires now, that's why I was looking for the upgrade. Thanks anyway.
Nam-D 4,080 Reputation points Microsoft External Staff Moderator

2026-10-07T15:54:05.44+00:00

Hi @Enrique Gustavo Dutra,

Unfortunately, Exchange Server 2019 has reached End of Support (Reference: Support for Exchange Server 2016 and Exchange Server 2019 ends.). If your organization is not enrolled in the Extended Security Updates (ESU) program, it will not receive any new security updates after EOS date.

Based on the Microsoft documentation referenced above, organizations that are not participating in the ESU program should migrate to Exchange Server Subscription Edition (SE) to continue receiving the latest security updates and ongoing support.

I understand the urgency of the situation and the impact this ongoing attack may have on your environment. However, this is a user-to-user support forum, and no one here, including myself, has the ability to provide Microsoft patch files or grant access to updates that are not publicly available.

Thank you for your understanding.
Enrique Gustavo Dutra 0 Reputation points MVP

2026-10-07T16:04:37.3866667+00:00

Thank you very much and thanks for the clarification.