5.9
MEDIUM CVSS 4.0
CVE-2025-62492
Heap out-of-bounds read in js_typed_array_indexOf in QuickJS
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 one element past the end of the array. This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.

INFO

Published Date :

Oct. 16, 2025, 4:15 p.m.

Last Modified :

Oct. 16, 2025, 4:15 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2025-62492 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM 14ed7db2-1595-443d-9d34-6215bf890778
CVSS 4.0 MEDIUM [email protected]
Solution
Address precision errors in TypedArray.prototype.indexOf with negative fromIndex to prevent out-of-bounds reads.
  • Update the QuickJS engine to the latest version.
  • Apply relevant patches for TypedArray.prototype.indexOf.
  • Validate index calculations involving floating-point numbers.
  • Sanitize negative fromIndex inputs carefully.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-62492.

URL Resource
https://bellard.org/quickjs/Changelog
https://issuetracker.google.com/434194797
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-62492 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-62492 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-62492 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-62492 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 16, 2025

    Action Type Old Value New Value
    Added 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 one element past the end of the array. This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
    Added CVSS V4.0 AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-125
    Added Reference https://bellard.org/quickjs/Changelog
    Added Reference https://issuetracker.google.com/434194797
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 5.9
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
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SS Confidentiality
SS Integrity
SS Availability