Werk #19589: Fixed crash in RRD creation for service names containing a null byte

Component

Core & setup

Title

Fixed crash in RRD creation for service names containing a null byte

Date

Jun 30, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

3.0.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p9 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.4.0p34 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

Previously, if a service description contained an embedded null byte — for example a stray NUL character emitted by some SNMP devices in a service name like PDU Bank B6 — the creation of the RRD database for that service crashed with the following error, and a crash report was generated:

ValueError: embedded null byte

As a result, no performance data (and therefore no graphs) could be stored for the affected service.

This has been fixed. The service name is now sanitized before it is used to build the RRD file path, so RRD creation no longer crashes and the performance data for the affected service is stored again.

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