{"id":"DEBIAN-CVE-2025-62494","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.","modified":"2026-09-01T20:05:55.571807772Z","published":"2025-10-16T16:15:39.943Z","upstream":["CVE-2025-62494"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-62494"}],"affected":[{"package":{"name":"quickjs","ecosystem":"Debian:13","purl":"pkg:deb/debian/quickjs?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2025.04.26-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-62494.json"}},{"package":{"name":"quickjs","ecosystem":"Debian:14","purl":"pkg:deb/debian/quickjs?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2025.04.26-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-62494.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}