CVE-2026-123555
Full vulnerability record from the local CVENow database.
Description
Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.
Severity
HIGH
CVSS score
8.7
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-11-08 02:16:47.313000
Last modified
2026-11-08 02:16:47.443000
View original CVE JSON
{
"id": "CVE-2026-123555",
"sourceIdentifier": "[email protected]",
"published": "2026-11-08T02:16:47.313",
"lastModified": "2026-11-08T02:16:47.443",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "ZcashFoundation",
"product": "zebra",
"defaultStatus": "unaffected",
"packageURL": "pkg:cargo/zebrad",
"versions": [
{
"version": "2.3.0",
"lessThan": "7.0.0",
"versionType": "semver",
"status": "affected"
},
{
"version": "7.0.0",
"versionType": "semver",
"status": "unaffected"
}
]
},
{
"vendor": "ZcashFoundation",
"product": "zebra",
"defaultStatus": "unaffected",
"packageURL": "pkg:cargo/zebra-consensus",
"versions": [
{
"version": "1.0.0-beta.46",
"lessThan": "18.0.0",
"versionType": "semver",
"status": "affected"
},
{
"version": "18.0.0",
"versionType": "semver",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"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": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"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
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-755"
}
]
}
],
"references": [
{
"url": "https://github.com/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a",
"source": "[email protected]"
},
{
"url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x",
"source": "[email protected]"
},
{
"url": "https://www.vulncheck.com/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures",
"source": "[email protected]"
}
]
}