The language converter in MediaWiki before 1.27.4, 1.28.x before 1.28.3, and 1.29.x before 1.29.2 allows attackers to replace text inside tags via a rule definition followed by "a lot of junk."
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2017-8814.json"