CVE-2025-62492

Technical Description

A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.

* The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.

* If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:

$$d_{new} = d + \text{len}$$

* Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.

* The result is then converted to an integer index $k$: $k = \text{len}$.

* The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is on

Remediation

Check the references section for vendor advisories and patches from quickjs_project. Update quickjs to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References