An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. An auto-block can occur for an untrusted X-Forwarded-For header.
An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. There is XSS in Wikibase date formatting via wikibase-time-precision-* fields. This allows JavaScript execution by staff/admin users who do not intentionally have the editsitejs capability.
An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. CheckUser TokenManager insecurely uses AES-CTR encryption with a repeated (aka re-used) nonce, allowing an adversary to decrypt.
An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. When installing with a pre-existing data directory that has weak permissions, the SQLite files are created with file mode 0644, i.e., world readable to local users. These files include credentials data.
In the GrowthExperiments extension for MediaWiki through 1.39, the growthmanagementorlist API allows blocked users (blocked in ApiManageMentorList) to enroll as mentors or edit any of their mentorship-related properties.
An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. SpecialMobileHistory allows remote attackers to cause a denial of service because database queries are slow.
An issue was discovered in MediaWiki before 1.35.9, 1.36.x through 1.38.x before 1.38.5, and 1.39.x before 1.39.1. E-Widgets does widget replacement in HTML attributes, which can lead to XSS, because widget authors often do not expect that their widget is executed in an HTML attribute context.
An issue was discovered in MediaWiki before 1.35.8, 1.36.x and 1.37.x before 1.37.5, and 1.38.x before 1.38.3. HTMLUserTextField exposes the existence of hidden users.
An issue was discovered in MediaWiki before 1.35.8, 1.36.x and 1.37.x before 1.37.5, and 1.38.x before 1.38.3. When changes made by an IP address are reassigned to a user (using reassignEdits.php), the changes will still be attributed to the IP address on Special:Contributions when doing a range lookup.
An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.