CVE-2025-62494
Unknown
Unknown - Not Provided
BaseFortify
Publication date: 2025-10-16
Last updated on: 2025-10-29
Assigner: Google Inc.
Description
Description
A type confusion vulnerability exists in the handling of the string addition (+) operation within the QuickJS engine.
* The code first checks if the left-hand operand is a string.
* It then attempts to convert the right-hand operand to a primitive value using JS_ToPrimitiveFree. This conversion can trigger a callback (e.g., toString or valueOf).
* During this callback, an attacker can modify the type of the left-hand operand in memory, changing it from a string to a different type (e.g., an object or an array).
* The code then proceeds to call JS_ConcatStringInPlace, which still treats the modified left-hand value as a string.
This mismatch between the assumed type (string) and the actual type allows an attacker to control the data structure being processed by the concatenation logic, resulting in a type confusion condition. This can lead to out-of-bounds memory access, potentially resulting in memory corruption and arbitrary code execution in the context of the QuickJS runtime.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| quickjs_project | quickjs | to 2025-09-13 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-704 | The product does not correctly convert an object, resource, or structure from one type to a different type. |
