CVE-2026-18140
Full vulnerability record from the local CVENow database.
Description
Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via a single small HTTP request containing deeply nested JSON to a smithy-rs generated server. To remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild.
Severity
HIGH
CVSS score
8.7
(v4.0)
Vulnerability status
Analyzed
Source identifier
ff89ba41-3aa1-4d27-914a-91399e9639e5
Published
2026-07-30 19:17:26.457000
Last modified
2026-10-23 22:10:00.160000
View original CVE JSON
{
"id": "CVE-2026-18140",
"sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"published": "2026-07-30T19:17:26.457",
"lastModified": "2026-10-23T22:10:00.160",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via a single small HTTP request containing deeply nested JSON to a smithy-rs generated server.\n\n\n\nTo remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild."
},
{
"lang": "es",
"value": "Recursión incontrolada en la ruta de omisión de clave desconocida del crate de tiempo de ejecución aws-smithy-json anterior a 0.62.7, que el generador de código smithy-rs invoca desde cada deserializador de estructura generado, podría permitir a usuarios remotos no autenticados causar una denegación de servicio (aborto de proceso por agotamiento de pila) a través de una única pequeña solicitud HTTP que contiene JSON profundamente anidado a un servidor generado por smithy-rs.\n\nPara remediar este problema, los usuarios deberían actualizar a aws-smithy-json 0.62.7 o posterior y reconstruir."
}
],
"affected": [
{
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"affectedData": [
{
"vendor": "AWS",
"product": "aws-smithy-json",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0.32.0",
"lessThanOrEqual": "0.62.6",
"versionType": "custom",
"status": "affected"
}
]
}
]
}
],
"metrics": {
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"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
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"cvssData": {
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"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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": 8.7,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"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": [
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"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-30T19:12:34.733029Z",
"id": "CVE-2026-18140",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
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{
"technicalImpact": "partial"
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"role": "CISA Coordinator",
"version": "2.0.3"
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"description": [
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"value": "CWE-674"
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"configurations": [
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"nodes": [
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"operator": "OR",
"negate": false,
"cpeMatch": [
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"references": [
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"url": "https://aws.amazon.com/security/security-bulletins/2026-067-aws/",
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
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},
{
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"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
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{
"url": "https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56",
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
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}