Word.ws English Dictionary

billion laughs

billion laughs noun: a type of denial-of-service attack which is aimed at parsers of XML documents, based on defining entities that expand to large numbers of copies of other entities.

Noun

billion laughs pl (plural only)

  1. (plural, plural-only, computer security) A type of denial-of-service attack which is aimed at parsers of XML documents, based on defining entities that expand to large numbers of copies of other entities.
    • The XML billion laughs DoS attack simply starts by declaring an XML document with an entity named lol (hence the name laugh gets associated with it, but in a general case it can be any valid name).2016, Prakhar Prasad, Mastering Modern Web Penetration Testing, Packt Publishing Ltd, →ISBN, page 193

Origin of billion laughs

In the most frequently cited example of such an attack, the first entity is the string lol (“laugh out loud”).

Questions about billion laughs

What does billion laughs mean?
Billion laughs means a type of denial-of-service attack which is aimed at parsers of XML documents, based on defining entities that expand to large numbers of copies of other entities.
What part of speech is billion laughs?
Billion laughs is a noun.

Words near billion laughs in the dictionary

  1. Billinudgel
  2. billio
  3. billion
  4. billion dollar question
  5. billion dollar questions
  6. billion laughs
  7. billion laughs attacks
  8. billion-dollar grass
  9. billion-dollar question
  10. billion-dollar questions
  11. billionaire

Source and license

Adapted from Wiktionary: billion laughs (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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