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Werk #18992: Move Customer Identifier string to SAN Extension

Component Core & setup
Title Move Customer Identifier string to SAN Extension
Date Feb 18, 2026
Level Trivial Change
Class Bug Fix
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
2.6.0b1
Not yet released
Checkmk MSP (CME)
2.5.0b1
Not yet released
Checkmk MSP (CME)

In Checkmk Ultimate MT (MSP), we have moved the Customer Identifier string from the Common Name (CN) of the Customer Broker Certificate Authority to the Subject Alternative Name (SAN) extension. This change resolves the previous character limit on the X.509 Common Name, which formerly prevented customers with long identifiers from generating broker certificates.

Every new broker certificate created within Checkmk will automatically include this property.

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