A global-buffer-overflow (out-of-bounds read) exists in GLib's g_date_time_get_ymd() function, triggered when operating on an invalid GDateTime object produced by g_date_time_add_full(). The g_date_time_add_full() function does not validate that the resulting date falls within the supported range (years 1–9999), allowing construction of a GDateTime with a negative or zero days field. When any getter function (e.g., g_date_time_get_month(), g_date_time_get_year()) is subsequently called, the internal g_date_time_get_ymd() routine computes a negative array index, causing a 2-byte OOB read from adjacent global data.