'bug-ridden' originates from English, specifically the words 'bug' and 'ridden'. 'bug' ultimately comes from Middle English 'bugge' (originally meaning 'a frightening creature, goblin' and later used for 'insect' and figuratively for a 'defect'), and 'ridden' is the past participle of Old English 'rīdan' (modern 'ride'), used in compounds to mean 'afflicted by' or 'full of'.

'bug-ridden' developed as part of the productive English pattern X-ridden (e.g. 'disease-ridden'). The sense of 'bug' shifted from 'goblin' (Middle English) to 'insect' (early modern English) and then to 'defect' in mechanical contexts in the late 19th/early 20th century, later extending to software; combined with 'ridden' this produced the modern compound 'bug-ridden'.

Initially it primarily meant 'infested with insects', but over time it evolved to include the figurative meaning 'full of defects or errors' (especially for machines and software).