CVE-2025-62494

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Source
https://cve.org/CVERecord?id=CVE-2025-62494
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-62494.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-62494
Downstream
Published
2025-10-16T16:15:39.943Z
Modified
2026-04-10T05:33:07.437092Z
Severity
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Git /

Affected ranges

Database specific

unresolved_ranges 
[
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "fixed": "2025-09-13"
            }
        ]
    }
]
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-62494.json"