{"cve":"CVE-2025-62495","nvd":{"published":"2025-10-16T16:15:40.110","modified":"2026-10-19T16:10:00.260","status":"Analyzed","description":"An integer overflow vulnerability exists in the QuickJS regular expression engine (libregexp) due to an inconsistent representation of the bytecode buffer size.\n\n  *  The regular expression bytecode is stored in a DynBuf structure, which correctly uses a $\\text{size}\\_\\text{t}$ (an unsigned type, typically 64-bit) for its size member.\n\n\n  *  However, several functions, such as re_emit_op_u32 and other internal parsing routines, incorrectly cast or store this DynBuf $\\text{size}\\_\\text{t}$ value into a signed int (typically 32-bit).\n\n\n  *  When a large or complex regular expression (such as those generated by a recursive pattern in a Proof-of-Concept) causes the bytecode size to exceed $2^{31}$ bytes (the maximum positive value for a signed 32-bit integer), the size value wraps around, resulting in a negative integer when stored in the int variable (Integer Overflow).\n\n\n  *  This negative value is subsequently used in offset calculations. For example, within functions like re_parse_disjunction, the negative size is used to compute an offset (pos) for patching a jump instruction.\n\n\n  *  This negative offset is then incorrectly added to the buffer pointer (s->byte\\_code.buf + pos), leading to an out-of-bounds write on the first line of the snippet below:\n\nput_u32(s->byte_code.buf + pos, len);","cvss_v4":{"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","score":7.1},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-191"],"references":["https://bellard.org/quickjs/Changelog","https://issuetracker.google.com/434196926"],"products":["quickjs_project:quickjs"],"source":"nvd","synced_at":"2026-10-19T22:12:35.277909958+00:00"},"epss":{"cve":"CVE-2025-62495","score":0.00457,"percentile":0.39408,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}