CVE-2026-32129
HIGH
CVSS 8.7
No EPSS data
Description
soroban-poseidon provides Poseidon and Poseidon2 cryptographic hash functions for Soroban smart contracts. Poseidon V1 (PoseidonSponge) accepts variable-length inputs without injective padding. When a caller provides fewer inputs than the sponge rate (inputs.len() < T - 1), unused rate positions are implicitly zero-filled. This allows trivial hash collisions: for any input vector [m1, ..., mk] hashed with a sponge of rate > k, hash([m1, ..., mk]) equals hash([m1, ..., mk, 0]) because both produce identical pre-permutation states. This affects any use of PoseidonSponge or poseidon_hash where the number of inputs is less than T - 1 (e.g., hashing 1 input with T=3). Poseidon2 (Poseidon2Sponge) is not affected.
CVSS details
EPSS
This CVE is not currently listed in the EPSS dataset.
Show JSON
{
"cve": {
"id": "CVE-2026-32129",
"cveTags": [],
"metrics": {
"cvssMetricV40": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 8.7,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/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",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"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"
}
}
]
},
"published": "2026-03-12T18:16:25.097",
"references": [
{
"url": "https://github.com/stellar/rs-soroban-poseidon/pull/10",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/stellar/rs-soroban-poseidon/releases/tag/v25.0.1",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/stellar/rs-soroban-poseidon/security/advisories/GHSA-g2p6-hh5v-7hfm",
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Primary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-328"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "soroban-poseidon provides Poseidon and Poseidon2 cryptographic hash functions for Soroban smart contracts. Poseidon V1 (PoseidonSponge) accepts variable-length inputs without injective padding. When a caller provides fewer inputs than the sponge rate (inputs.len() < T - 1), unused rate positions are implicitly zero-filled. This allows trivial hash collisions: for any input vector [m1, ..., mk] hashed with a sponge of rate > k, hash([m1, ..., mk]) equals hash([m1, ..., mk, 0]) because both produce identical pre-permutation states. This affects any use of PoseidonSponge or poseidon_hash where the number of inputs is less than T - 1 (e.g., hashing 1 input with T=3). Poseidon2 (Poseidon2Sponge) is not affected."
},
{
"lang": "es",
"value": "soroban-poseidon proporciona funciones hash criptogr\u00e1ficas Poseidon y Poseidon2 para contratos inteligentes de Soroban. Poseidon V1 (PoseidonSponge) acepta entradas de longitud variable sin relleno inyectivo. Cuando un llamador proporciona menos entradas que la tasa de la esponja (inputs.len() < T - 1), las posiciones de tasa no utilizadas se rellenan impl\u00edcitamente con ceros. Esto permite colisiones hash triviales: para cualquier vector de entrada [m1, ..., mk] hasheado con una esponja de tasa > k, hash([m1, ..., mk]) es igual a hash([m1, ..., mk, 0]) porque ambos producen estados de pre-permutaci\u00f3n id\u00e9nticos. Esto afecta cualquier uso de PoseidonSponge o poseidon_hash donde el n\u00famero de entradas es menor que T - 1 (p. ej., hashear 1 entrada con T=3). Poseidon2 (Poseidon2Sponge) no se ve afectado."
}
],
"lastModified": "2026-04-16T14:47:16.733",
"sourceIdentifier": "security-advisories@github.com"
}
}