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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 13 Mar 2026 10:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Stellar
Stellar rs-soroban-poseidon |
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| Vendors & Products |
Stellar
Stellar rs-soroban-poseidon |
Thu, 12 Mar 2026 18:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Poseidon V1 variable-length input collision via implicit zero-padding | |
| Weaknesses | CWE-328 | |
| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-03-12T17:47:10.717Z
Reserved: 2026-03-10T22:19:36.545Z
Link: CVE-2026-32129
No data.
Status : Awaiting Analysis
Published: 2026-03-12T18:16:25.097
Modified: 2026-03-12T21:07:53.427
Link: CVE-2026-32129
No data.
OpenCVE Enrichment
Updated: 2026-03-13T09:50:39Z
Weaknesses