CVE-2026-123555 (GCVE-0-2026-123555)
Vulnerability from cvelistv5 – Published: 2026-11-08 01:37 – Updated: 2026-11-08 01:37
VLAI
EPSS
VEX
Title
Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures
Summary
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
CWE
- CWE-755 - Improper Handling of Exceptional Conditions
Assigner
VulnCheck
CNA
References
3 references
| URL | Tags |
|---|---|
| https://github.com/ZcashFoundation/zebra/security… | vendor-advisory |
| https://github.com/ZcashFoundation/zebra/commit/e… | patch |
| https://www.vulncheck.com/advisories/zebra-2.3.0-… | third-party-advisory |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| ZcashFoundation | zebra |
Affected:
2.3.0 , < 7.0.0
(semver)
Unaffected: 7.0.0 (semver) |
|
| ZcashFoundation | zebra |
Affected:
1.0.0-beta.46 , < 18.0.0
(semver)
Unaffected: 18.0.0 (semver) |
Date Public
2026-10-22 00:00
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"packageURL": "pkg:cargo/zebrad",
"product": "zebra",
"vendor": "ZcashFoundation",
"versions": [
{
"lessThan": "7.0.0",
"status": "affected",
"version": "2.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.0.0",
"versionType": "semver"
}
]
},
{
"defaultStatus": "unaffected",
"packageURL": "pkg:cargo/zebra-consensus",
"product": "zebra",
"vendor": "ZcashFoundation",
"versions": [
{
"lessThan": "18.0.0",
"status": "affected",
"version": "1.0.0-beta.46",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "18.0.0",
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}
]
}
],
"cpeApplicability": [
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"nodes": [
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"versionEndExcluding": "7.0.0",
"versionStartIncluding": "2.3.0",
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},
{
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"versionEndExcluding": "18.0.0",
"versionStartIncluding": "1.0.0-beta.46",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "x15-eth"
},
{
"lang": "en",
"type": "coordinator",
"value": "mpguerra"
},
{
"lang": "en",
"type": "remediation developer",
"value": "conradoplg"
},
{
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"type": "remediation reviewer",
"value": "upbqdn"
}
],
"datePublic": "2026-10-22T00:00:00.000Z",
"descriptions": [
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"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."
}
],
"metrics": [
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"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"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",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE"
},
"format": "CVSS"
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{
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"attackVector": "NETWORK",
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"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
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"descriptions": [
{
"cweId": "CWE-755",
"description": "Improper Handling of Exceptional Conditions",
"lang": "en",
"type": "CWE"
}
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],
"providerMetadata": {
"dateUpdated": "2026-11-08T01:37:57.593Z",
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"shortName": "VulnCheck"
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"references": [
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"name": "GitHub Security Advisory (GHSA-jq45-ghw5-v37x)",
"tags": [
"vendor-advisory"
],
"url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x"
},
{
"name": "Patch Commit",
"tags": [
"patch"
],
"url": "https://github.com/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a"
},
{
"name": "VulnCheck Advisory: Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures",
"tags": [
"third-party-advisory"
],
"url": "https://www.vulncheck.com/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures"
}
],
"title": "Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures",
"x_generator": {
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}
}
},
"cveMetadata": {
"assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"assignerShortName": "VulnCheck",
"cveId": "CVE-2026-123555",
"datePublished": "2026-11-08T01:37:57.593Z",
"dateReserved": "2026-11-06T00:50:45.482Z",
"dateUpdated": "2026-11-08T01:37:57.593Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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