Executive brief
a2ui is a UI framework used to build web applications. A vulnerability in the data model processor allows attackers to read sensitive internal properties (such as toString, constructor, and __proto__) through specially crafted JSON path inputs, potentially exposing sensitive information about the application's internal state.
Technical details
The vulnerability is a prototype chain traversal flaw in the getDataByPath function of model-processor.ts in a2ui versions 0.8, 0.9, and 1.0. The vulnerable code accessed object properties directly via current[segment] without checking if the property was an own property, allowing attackers to traverse inherited prototype chain properties. An attacker can craft a JSON pointer path to access and read inherited properties such as toString, valueOf, constructor, and __proto__ instead of legitimate data values. The attack is remotely initiated and requires network access, but does not require authentication. The fix (commit 1b3bff234661ce922cbc3771be642b23ec9fd0fa) adds an Object.prototype.hasOwnProperty.call() check to ensure only own properties are accessible, with a safe fallback to null for invalid paths.
Affected products
- a2ui-project a2ui 0.8, 0.9, 1.0
Timeline
- 2026-09-16: disclosed: CVE-2026-92357 published
- 2026-09-14: patched: Patch commit 1b3bff234661ce922cbc3771be642b23ec9fd0fa