CVE-2026-32129 – Poseidon V1 variable-length input collision via implicit zero-padding

CVE ID :CVE-2026-32129

Published : March 12, 2026, 5:47 p.m. | 39 minutes ago

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() 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.

Severity: 0.0 | NA

Visit the link for more details, such as CVSS details, affected products, timeline, and more…