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:*:*:*:*:*:*:*:*"
]
}