Update january-2026.md

Author: xboxeer

articles/mysql/flexible-server/release-notes/january-2026.md

@@ -17,6 +17,12 @@ We're excited to announce the January 2026 version of Azure Database for MySQL F
 
 This new version introduces a range of new features and enhancements, resolves known issues, and includes essential security patches to ensure optimal performance and security.
 
+> [!IMPORTANT]
+> - For Azure Database for MySQL instances in the Azure Public Cloud, an internal certificate is scheduled to expire by the end of February 2026. As a result, the maintenance reschedule window for this cycle is limited to dates before the end of February. Postponing maintenance beyond February may cause the server to become unreachable after the certificate expires. Therefore, rescheduling past the end of February is not supported for this maintenance event.
+> - For some Azure Database for MySQL instances in Azure National Clouds, the certificate issued by the current Certificate Authority (CA) is expected to expire before February 7, 2026. Once the certificate expires, client connections to the server will fail, resulting in service unavailability.
+To assess whether your server is impacted, you can verify the certificate expiration date from a client environment using the following command:`openssl s_client -starttls mysql -connect <server_dns>:3306`. For affected servers, the maintenance reschedule window is limited and cannot be freely postponed, as further delay increases the risk of certificate expiration and client connection failures. In some cases, if the server was restarted recently, the certificate may have been automatically refreshed. If you believe this applies to your server, please open an Azure Support case. After validation, we can extend the maintenance reschedule window up to the end of February.
+> - During this maintenance cycle, two major global events—**Super Bowl (February 5–10)** and **Lunar New Year (February 16–23)**—may limit our ability to fully honor all customers’ Custom Maintenance Window (CMW) preferences during initial scheduling. As a result, some servers with CMW enabled may be assigned a maintenance date outside of their preferred window. You can still reschedule the maintenance in the Azure portal to better align with these event periods or your original CMW preference.
+
 ## Engine version changes
 
 There will be no engine version changes in this version.