An issue was discovered in the GrowthExperiments extension for MediaWiki through 1.39.3. The UserImpactHandler for GrowthExperiments inadvertently returns the timezone preference for arbitrary users, which can be used to de-anonymize users.
{ "severity": "Medium", "cpes": [ "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*" ] }