loose lips sink ships

English

Shortening of a wartime slogan from World War II.

Saying too much or releasing confidential information can have dangerous consequences.
- 2000, Margaret Atwood, The Blind Assassin, Anchor, published 2007, →ISBN, page 448:
  Loose Lips Sink Ships, said the wartime poster. Of course the ships will all sink anyway, sooner or later.
- 2014, Crystal Chan, Bird, Random House, →ISBN, page 59:
  ‘Loose lips sink ships,’ she spat at Dad once, when they were arguing about Grandpa, but ‘loose lips killed our son.’

saying too much or releasing confidential information can have dangerous consequences

Chinese:
Mandarin: 禍從口出 / 祸从口出 (zh) (huòcóngkǒuchū)
Finnish: älä puhu sivu suun
French: propos inconsidérés, bateaux coulés
German: Reden ist Silber, Schweigen ist Gold (de)
Japanese: please add this translation if you can
Mongolian: амсар сэтэрхий аяганд цай бүү хий, ам сул хүнд нууцаа бүү дэлгэ (amsar seterxii ajagand caj büü xii, am sul xünd nuucaa büü delge)
Polish: nieostrożne gadanie zatapia statki
Portuguese: o peixe morre pela boca (pt)
Russian: болту́н — нахо́дка для шпио́на (boltún — naxódka dlja špióna, literally “a chatterbox is a treasure for a spy”)
Spanish: por la boca muere el pez, palabra y piedra suelta no tiene vuelta (literally “a word and stone once thrown cannot return”), palabra de boca, piedra de honda (literally “word from the mouth, stone from a slingshot”)