Werk #19040: check_cert: fix potentially empty Subject CN line even when Subject CN is available

Component

Checks & agents

Title

check_cert: fix potentially empty Subject CN line even when Subject CN is available

Date

Feb 17, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

2.6.0b1 Not yet released	Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME)
2.5.0b1 Not yet released	Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME)

Certificate monitoring now correctly displays the Subject CN (common name) of certificates when it is present.

Previously, the Subject CN field could appear empty even though the certificate contained this information, which might have caused confusion or difficulty in identifying certificates.

With this fix, the Subject CN reliably appears in the monitoring interface, improving clarity and usability.

No user action is required to benefit from this update.

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