{ "dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": { "cveId": "CVE-2025-62495", "assignerOrgId": "14ed7db2-1595-443d-9d34-6215bf890778", "state": "PUBLISHED", "assignerShortName": "Google", "dateReserved": "2025-10-15T08:47:41.878Z", "datePublished": "2025-10-16T15:51:58.953Z", "dateUpdated": "2025-10-16T17:42:15.865Z" }, "containers": { "cna": { "affected": [ { "collectionURL": "https://bellard.org/quickjs/", "defaultStatus": "unaffected", "packageName": "libregexp", "product": "QuickJS", "vendor": "QuickJS", "versions": [ { "lessThan": "2025-09-13", "status": "affected", "version": "2025-04-26", "versionType": "date" } ] } ], "credits": [ { "lang": "en", "type": "finder", "value": "Google Big Sleep" } ], "datePublic": "2025-07-24T22:00:00.000Z", "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

An integer overflow vulnerability exists in the QuickJS regular expression engine (libregexp) due to an inconsistent representation of the bytecode buffer size.

  1. 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.

  2. 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).

  3. 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).

  4. 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.

  5. 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:

    put_u32(s->byte_code.buf + pos, len);


" } ], "value": "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);" } ], "impacts": [ { "capecId": "CAPEC-175", "descriptions": [ { "lang": "en", "value": "CAPEC-175 Code Inclusion" } ] } ], "metrics": [ { "cvssV4_0": { "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "baseScore": 7.1, "baseSeverity": "HIGH", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-191", "description": "CWE-191 Integer Underflow (Wrap or Wraparound)", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "14ed7db2-1595-443d-9d34-6215bf890778", "shortName": "Google", "dateUpdated": "2025-10-16T15:51:58.953Z" }, "references": [ { "url": "https://bellard.org/quickjs/Changelog" }, { "url": "https://issuetracker.google.com/434196926" } ], "source": { "discovery": "UNKNOWN" }, "title": "Type confusion in string addition in QuickJS", "x_generator": { "engine": "Vulnogram 0.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2025-10-16T17:40:14.439633Z", "id": "CVE-2025-62495", "options": [ { "Exploitation": "poc" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-16T17:42:15.865Z" } } ] } }