{"schemaVersion":3,"id":"CVE-2026-48516","aliases":["GHSA-q2h6-ghwm-5qm8"],"status":"published","duplicateOf":null,"title":null,"description":"MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, InterfaceLookupFormatter<TKey,TElement> constructs an internal Dictionary<TKey, IGrouping<TKey,TElement>> with the default equality comparer instead of the security-aware comparer supplied by options.Security.GetEqualityComparer<TKey>(). 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