CVE-2025-62495 (GCVE-0-2025-62495)
Vulnerability from cvelistv5 – Published: 2025-10-16 15:51 – Updated: 2025-10-16 17:42
VLAI?
Title
Type confusion in string addition in QuickJS
Summary
An integer overflow vulnerability exists in the QuickJS regular expression engine (libregexp) due to an inconsistent representation of the bytecode buffer size.
* 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.
* 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).
* 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).
* 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.
* 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);
Severity ?
CWE
- CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
References
Credits
Google Big Sleep
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2025-62495",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-10-16T17:40:14.439633Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-10-16T17:42:15.865Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"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": "\u003cp\u003eAn integer overflow vulnerability exists in the QuickJS regular expression engine (\u003ccode\u003elibregexp\u003c/code\u003e) due to an \u003cb\u003einconsistent representation of the bytecode buffer size\u003c/b\u003e.\u003c/p\u003e\u003col\u003e\u003cli\u003e\u003cp\u003eThe regular expression bytecode is stored in a \u003ccode\u003eDynBuf\u003c/code\u003e structure, which correctly uses a $\\text{size}\\_\\text{t}$ (an unsigned type, typically 64-bit) for its \u003ccode\u003esize\u003c/code\u003e member.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHowever, several functions, such as \u003ccode\u003ere_emit_op_u32\u003c/code\u003e and other internal parsing routines, incorrectly cast or store this \u003ccode\u003eDynBuf\u003c/code\u003e $\\text{size}\\_\\text{t}$ value into a signed \u003cb\u003eint\u003c/b\u003e (typically 32-bit).\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eWhen 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 \u003cb\u003e$2^{31}$ bytes\u003c/b\u003e (the maximum positive value for a signed 32-bit integer), the size value wraps around, resulting in a \u003cb\u003enegative integer\u003c/b\u003e when stored in the \u003ccode\u003eint\u003c/code\u003e variable (Integer Overflow).\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThis negative value is subsequently used in offset calculations. For example, within functions like \u003ccode\u003ere_parse_disjunction\u003c/code\u003e, the negative size is used to compute an offset (\u003ccode\u003epos\u003c/code\u003e) for patching a jump instruction.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThis negative offset is then incorrectly added to the buffer pointer (\u003ccode\u003es-\u0026gt;byte\\_code.buf + pos\u003c/code\u003e), leading to an \u003cb\u003eout-of-bounds write\u003c/b\u003e on the first line of the snippet below:\u003c/p\u003e\u003cblockquote\u003e\u003cp\u003e\u003ccode\u003eput_u32(s-\u0026gt;byte_code.buf + pos, len);\u003c/code\u003e\u003c/p\u003e\u003c/blockquote\u003e\u003c/li\u003e\u003c/ol\u003e\u003cbr\u003e"
}
],
"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-\u003ebyte\\_code.buf + pos), leading to an out-of-bounds write on the first line of the snippet below:\n\nput_u32(s-\u003ebyte_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": {
"dateUpdated": "2025-10-16T15:51:58.953Z",
"orgId": "14ed7db2-1595-443d-9d34-6215bf890778",
"shortName": "Google"
},
"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"
}
}
},
"cveMetadata": {
"assignerOrgId": "14ed7db2-1595-443d-9d34-6215bf890778",
"assignerShortName": "Google",
"cveId": "CVE-2025-62495",
"datePublished": "2025-10-16T15:51:58.953Z",
"dateReserved": "2025-10-15T08:47:41.878Z",
"dateUpdated": "2025-10-16T17:42:15.865Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2025-62495\",\"sourceIdentifier\":\"cve-coordination@google.com\",\"published\":\"2025-10-16T16:15:40.110\",\"lastModified\":\"2025-10-29T18:56:54.723\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"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-\u003ebyte\\\\_code.buf + pos), leading to an out-of-bounds write on the first line of the snippet below:\\n\\nput_u32(s-\u003ebyte_code.buf + pos, len);\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cve-coordination@google.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"ADJACENT\",\"attackComplexity\":\"HIGH\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"LOW\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"LOW\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"cve-coordination@google.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-191\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:quickjs_project:quickjs:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"2025-09-13\",\"matchCriteriaId\":\"AB84E2DC-74EA-4956-9521-C2B652B8E8C2\"}]}]}],\"references\":[{\"url\":\"https://bellard.org/quickjs/Changelog\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://issuetracker.google.com/434196926\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Exploit\",\"Issue Tracking\"]}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2025-62495\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-10-16T17:40:14.439633Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-10-16T17:41:50.821Z\"}}], \"cna\": {\"title\": \"Type confusion in string addition in QuickJS\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Google Big Sleep\"}], \"impacts\": [{\"capecId\": \"CAPEC-175\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-175 Code Inclusion\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 7.1, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"ADJACENT\", \"baseSeverity\": \"HIGH\", \"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\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"PASSIVE\", \"attackComplexity\": \"HIGH\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"HIGH\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"LOW\", \"vulnAvailabilityImpact\": \"LOW\", \"subConfidentialityImpact\": \"HIGH\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"QuickJS\", \"product\": \"QuickJS\", \"versions\": [{\"status\": \"affected\", \"version\": \"2025-04-26\", \"lessThan\": \"2025-09-13\", \"versionType\": \"date\"}], \"packageName\": \"libregexp\", \"collectionURL\": \"https://bellard.org/quickjs/\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2025-07-24T22:00:00.000Z\", \"references\": [{\"url\": \"https://bellard.org/quickjs/Changelog\"}, {\"url\": \"https://issuetracker.google.com/434196926\"}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"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-\u003ebyte\\\\_code.buf + pos), leading to an out-of-bounds write on the first line of the snippet below:\\n\\nput_u32(s-\u003ebyte_code.buf + pos, len);\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eAn integer overflow vulnerability exists in the QuickJS regular expression engine (\u003ccode\u003elibregexp\u003c/code\u003e) due to an \u003cb\u003einconsistent representation of the bytecode buffer size\u003c/b\u003e.\u003c/p\u003e\u003col\u003e\u003cli\u003e\u003cp\u003eThe regular expression bytecode is stored in a \u003ccode\u003eDynBuf\u003c/code\u003e structure, which correctly uses a $\\\\text{size}\\\\_\\\\text{t}$ (an unsigned type, typically 64-bit) for its \u003ccode\u003esize\u003c/code\u003e member.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eHowever, several functions, such as \u003ccode\u003ere_emit_op_u32\u003c/code\u003e and other internal parsing routines, incorrectly cast or store this \u003ccode\u003eDynBuf\u003c/code\u003e $\\\\text{size}\\\\_\\\\text{t}$ value into a signed \u003cb\u003eint\u003c/b\u003e (typically 32-bit).\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eWhen 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 \u003cb\u003e$2^{31}$ bytes\u003c/b\u003e (the maximum positive value for a signed 32-bit integer), the size value wraps around, resulting in a \u003cb\u003enegative integer\u003c/b\u003e when stored in the \u003ccode\u003eint\u003c/code\u003e variable (Integer Overflow).\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThis negative value is subsequently used in offset calculations. For example, within functions like \u003ccode\u003ere_parse_disjunction\u003c/code\u003e, the negative size is used to compute an offset (\u003ccode\u003epos\u003c/code\u003e) for patching a jump instruction.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThis negative offset is then incorrectly added to the buffer pointer (\u003ccode\u003es-\u0026gt;byte\\\\_code.buf + pos\u003c/code\u003e), leading to an \u003cb\u003eout-of-bounds write\u003c/b\u003e on the first line of the snippet below:\u003c/p\u003e\u003cblockquote\u003e\u003cp\u003e\u003ccode\u003eput_u32(s-\u0026gt;byte_code.buf + pos, len);\u003c/code\u003e\u003c/p\u003e\u003c/blockquote\u003e\u003c/li\u003e\u003c/ol\u003e\u003cbr\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-191\", \"description\": \"CWE-191 Integer Underflow (Wrap or Wraparound)\"}]}], \"providerMetadata\": {\"orgId\": \"14ed7db2-1595-443d-9d34-6215bf890778\", \"shortName\": \"Google\", \"dateUpdated\": \"2025-10-16T15:51:58.953Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2025-62495\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-10-16T17:42:15.865Z\", \"dateReserved\": \"2025-10-15T08:47:41.878Z\", \"assignerOrgId\": \"14ed7db2-1595-443d-9d34-6215bf890778\", \"datePublished\": \"2025-10-16T15:51:58.953Z\", \"assignerShortName\": \"Google\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…