{"id":"CVE-2026-32129","state":"PUBLISHED","title":"Poseidon V1 variable-length input collision via implicit zero-padding","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.","publishedAt":"2026-03-12T17:47:10.717Z","updatedAt":"2026-03-13T16:23:54.655Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["stellar rs-soroban-poseidon"],"affected":[{"vendor":"stellar","product":"rs-soroban-poseidon","versions":[{"version":"< 25.0.1","status":"affected"}]}],"references":["https://github.com/stellar/rs-soroban-poseidon/security/advisories/GHSA-g2p6-hh5v-7hfm","https://github.com/stellar/rs-soroban-poseidon/pull/10","https://github.com/stellar/rs-soroban-poseidon/releases/tag/v25.0.1"],"weaknesses":["CWE-328"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/32xxx/CVE-2026-32129.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-32129","state":"PUBLISHED","datePublished":"2026-03-12T17:47:10.717Z","dateUpdated":"2026-03-13T16:23:54.655Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-10T22:19:36.545Z"},"containers":{"cna":{"title":"Poseidon V1 variable-length input collision via implicit zero-padding","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."}],"affected":[{"vendor":"stellar","product":"rs-soroban-poseidon","versions":[{"version":"< 25.0.1","status":"affected"}]}],"references":[{"url":"https://github.com/stellar/rs-soroban-poseidon/security/advisories/GHSA-g2p6-hh5v-7hfm","name":"https://github.com/stellar/rs-soroban-poseidon/security/advisories/GHSA-g2p6-hh5v-7hfm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/stellar/rs-soroban-poseidon/pull/10","name":"https://github.com/stellar/rs-soroban-poseidon/pull/10","tags":["x_refsource_MISC"]},{"url":"https://github.com/stellar/rs-soroban-poseidon/releases/tag/v25.0.1","name":"https://github.com/stellar/rs-soroban-poseidon/releases/tag/v25.0.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-328","lang":"en","description":"CWE-328: Use of Weak Hash","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-12T17:47:10.717Z"},"source":{"advisory":"GHSA-g2p6-hh5v-7hfm","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-13T16:23:48.432393Z","id":"CVE-2026-32129","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-13T16:23:54.655Z"}}]}}}