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CVE-2025-62494 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  Google Inc.
CVSS-B 7.1 HIGH
Vector:  CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://bellard.org/quickjs/Changelog Google Inc.
https://issuetracker.google.com/434193023 Google Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-704 Incorrect Type Conversion or Cast Google Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-62494
NVD Published Date:
10/16/2025
NVD Last Modified:
10/16/2025
Source:
Google Inc.