CVE-2026-33228 Detail
Received
This CVE record has recently been published to the CVE List and has been included within the NVD dataset. Descriptionflatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "__proto__" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2. Metrics
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Weakness Enumeration
Quick InfoCVE Dictionary Entry:CVE-2026-33228 NVD Published Date: 03/20/2026 NVD Last Modified: 03/20/2026 Source: GitHub, Inc. |
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