CVE-2026-56114
Full vulnerability record from the local CVENow database.
Description
dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.
Severity
MEDIUM
CVSS score
6.0
(v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-06-23 17:17:09.163000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
"id": "CVE-2026-56114",
"sourceIdentifier": "[email protected]",
"published": "2026-06-23T17:17:09.163",
"lastModified": "2026-10-25T23:10:00.167",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory."
},
{
"lang": "es",
"value": "dhcpcd hasta 10.3.2, corregido en el commit 2f00c7b, contiene una vulnerabilidad de escritura fuera de límites de pila de un byte en dhcp6_makemessage() en src/dhcp6.c que permite a atacantes no autenticados en el mismo enlace escribir más allá de un búfer local fijo serializando un cuerpo de opción RFC6603 OPTION_PD_EXCLUDE sobredimensionado. Los atacantes pueden enviar un mensaje DHCPv6 ADVERTISE manipulado que contiene un IA_PD IAPREFIX /0 con un OPTION_PD_EXCLUDE válido utilizando una longitud de prefijo de exclusión de /121 a /128 para activar la escritura fuera de límites y potencialmente corromper la memoria de pila adyacente."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "NetworkConfiguration",
"product": "dhcpcd",
"defaultStatus": "affected",
"repo": "https://github.com/NetworkConfiguration/dhcpcd",
"packageURL": "pkg:github/NetworkConfiguration/dhcpcd",
"versions": [
{
"version": "0",
"lessThanOrEqual": "10.3.2",
"versionType": "semver",
"status": "affected"
},
{
"version": "2f00c7bfc408b6582d331932dfa47829c4819029",
"versionType": "git",
"status": "unaffected"
}
]
}
]
}
],
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"baseScore": 6.0,
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"attackVector": "ADJACENT",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
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"vulnConfidentialityImpact": "NONE",
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"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
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"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
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"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
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"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
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"type": "Primary",
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"id": "CVE-2026-56114",
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"weaknesses": [
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"type": "Secondary",
"description": [
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"configurations": [
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"references": [
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"source": "[email protected]",
"tags": [
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},
{
"url": "https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage",
"source": "[email protected]",
"tags": [
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}
]
}