cvedb.io
CVE-2025-62494
HIGH · CVSS 8.8
EPSS exploitation probability: 0%
Published 2025-10-16T16:15:39.943 · Last modified 2026-06-17T09:51:58.890

Summary

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 conc

Affected products

quickjs_project — quickjs

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.