CVE-2026-88255
Improper Validation of Unsafe Equivalence in Input in ZenHive mpp allows an unauthenticated remote client to pass the Tempo duplicate-submission gate twice with one signed transaction.
MPP.Methods.Tempo reserves the pre-broadcast dedup slot on the caller-supplied hex in reserve_hash_atomic/2, keyed through store_key/1 on tx.raw rather than on a canonical form of the transaction.
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The deserializer stores the caller's hex verbatim and accepts both recovery-id encodings, so one signed transaction submitted once with v=27 and once with v=0 yields two distinct reserve keys, and both pass the reserve and reach the broadcast path. The plug-level credential replay store is deliberately carved out for tempo in lib/mpp/replay.ex, leaving this reserve as the only gate, and the post-broadcast mark writes the canonical hash key that the raw-keyed reserve never reads.
What the duplicate submission yields depends on the node: a nonce-reuse rejection fails closed, while a node that answers with the canonical hash for an already-known transaction returns a second valid Payment-Receipt for a single on-chain payment.
This issue affects mpp: from 0.2.0 before 0.16.2.
CVSS
- Versión: 4.0
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/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
- Puntuación base: 6.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.52%
- Percentil entre todas las CVEs puntuadas: 43
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-1289
Referencias
- https://cna.erlef.org/cves/CVE-2026-88255.html
- https://github.com/ZenHive/mpp/commit/e12bd4a1cea2e97c2a01fc059c48e5594a7b4a43
- https://github.com/ZenHive/mpp/commit/f8904666061fbab695874856d8fcd02c471dfe1b
- https://github.com/ZenHive/mpp/security/advisories/GHSA-8x7x-5j8g-8hcx
- https://osv.dev/vulnerability/EEF-CVE-2026-88255
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-88255",
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"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-88255",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-16T14:49:50.266563Z"
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{
"type": "Secondary",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"cvssData": {
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"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 6.3,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/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",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "NONE",
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"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "LOW",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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"affected": [
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"affectedData": [
{
"cpes": [
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],
"repo": "https://github.com/ZenHive/mpp",
"vendor": "ZenHive",
"modules": [
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],
"product": "mpp",
"versions": [
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"version": "0.2.0",
"lessThan": "0.16.2",
"versionType": "semver"
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],
"packageURL": "pkg:hex/mpp",
"packageName": "mpp",
"programFiles": [
"lib/mpp/methods/tempo.ex"
],
"collectionURL": "https://repo.hex.pm",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "'Elixir.MPP.Methods.Tempo':verify/2"
}
]
},
{
"cpes": [
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"versions": [
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"version": "f8904666061fbab695874856d8fcd02c471dfe1b",
"lessThan": "e12bd4a1cea2e97c2a01fc059c48e5594a7b4a43",
"versionType": "git"
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"packageURL": "pkg:github/zenhive/mpp",
"packageName": "zenhive/mpp",
"programFiles": [
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"collectionURL": "https://github.com",
"defaultStatus": "unaffected",
"programRoutines": [
{
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}
]
}
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}
],
"published": "2026-09-16T09:17:07.333",
"references": [
{
"url": "https://cna.erlef.org/cves/CVE-2026-88255.html",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
},
{
"url": "https://github.com/ZenHive/mpp/commit/e12bd4a1cea2e97c2a01fc059c48e5594a7b4a43",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
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{
"url": "https://github.com/ZenHive/mpp/commit/f8904666061fbab695874856d8fcd02c471dfe1b",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
},
{
"url": "https://github.com/ZenHive/mpp/security/advisories/GHSA-8x7x-5j8g-8hcx",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
},
{
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-88255",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"description": [
{
"lang": "en",
"value": "CWE-1289"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Improper Validation of Unsafe Equivalence in Input in ZenHive mpp allows an unauthenticated remote client to pass the Tempo duplicate-submission gate twice with one signed transaction.\n\nMPP.Methods.Tempo reserves the pre-broadcast dedup slot on the caller-supplied hex in reserve_hash_atomic/2, keyed through store_key/1 on tx.raw rather than on a canonical form of the transaction. The deserializer stores the caller's hex verbatim and accepts both recovery-id encodings, so one signed transaction submitted once with v=27 and once with v=0 yields two distinct reserve keys, and both pass the reserve and reach the broadcast path. The plug-level credential replay store is deliberately carved out for tempo in lib/mpp/replay.ex, leaving this reserve as the only gate, and the post-broadcast mark writes the canonical hash key that the raw-keyed reserve never reads.\n\nWhat the duplicate submission yields depends on the node: a nonce-reuse rejection fails closed, while a node that answers with the canonical hash for an already-known transaction returns a second valid Payment-Receipt for a single on-chain payment.\n\nThis issue affects mpp: from 0.2.0 before 0.16.2."
}
],
"lastModified": "2026-09-16T20:38:33.883",
"sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}