Stack overflow vulnerability in eslint before 9.26.0 when serializing objects with circular references in eslint/lib/shared/serialization.js. The exploit is triggered via the RuleTester.run() method, which validates test cases and checks for duplicates. During validation, the internal function checkDuplicateTestCase() is called, which in turn uses the isSerializable() function for serialization checks. When a circular reference object is passed in, isSerializable() enters infinite recursion, ultimately causing a stack overflow.

Withdrawn by the publisher.

Affected: npm: eslint

## Withdrawn Advisory This advisory has been withdrawn because RuleTester is used for testing rules during development and results in a error rather than crashing the application.

## Original Description

There is a Stack Overflow vulnerability in eslint before 9.26.0 when serializing objects with circular references in `eslint/lib/shared/serialization.js`. The exploit is triggered via the `RuleTester.run()` method, which validates test cases and checks for duplicates. During validation, the internal function `checkDuplicateTestCase()` is called, which in turn uses the `isSerializable()` function for serialization checks. When a circular reference object is passed in, `isSerializable()` enters infinite recursion, ultimately causing a Stack Overflow.

Affected: Ubuntu:20.04:LTS: eslint, Ubuntu:22.04:LTS: eslint, Ubuntu:24.04:LTS: eslint, Ubuntu:25.10: eslint, Ubuntu:26.04:LTS: eslint

Stack overflow vulnerability in eslint before 9.26.0 when serializing objects with circular references in eslint/lib/shared/serialization.js. The exploit is triggered via the RuleTester.run() method, which validates test cases and checks for duplicates. During validation, the internal function checkDuplicateTestCase() is called, which in turn uses the isSerializable() function for serialization checks. When a circular reference object is passed in, isSerializable() enters infinite recursion, ultimately causing a stack overflow.