CVE-2022-34750: Mediawiki

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

An issue was discovered in MediaWiki through 1.38.1. The lemma length of a Wikibase lexeme is currently capped at a thousand characters. Unfortunately, this length is not validated, allowing much larger lexemes to be created, which introduces various denial-of-service attack vectors within the Wikibase and WikibaseLexeme extensions. This is related to Special:NewLexeme and Special:NewProperty.

Affected products

• Mediawiki Mediawiki: up to and including 1.38.1

Published 2022-06-28. Last modified 2026-06-17.