14.3 seems to come from some Red Hat-specific GCC version, which can be reported as "gcc (GCC) 14.3.1 20250617 (Red Hat 14.3.1-2)". See these random examples I found by googling:

https://github.com/anthropics/claude-code/issues/40741 (gcc version "Red Hat 14.3" included in system version at the bottom)

https://docs.oracle.com/en/database/oracle/tuxedo/22/otxig/s...