---
id: RUSTSEC-2026-0330
title: Hybrid Encapsulation from Seed Panics on Short Seed
summary: Hybrid Encapsulation from Seed Panics on Short Seed
severity: none
vendor: libcrux-kem
product: libcrux-kem
ecosystem: rust
affected:
  - 'libcrux-kem >= 0.0.0-0, < 0.0.10'
patched:
  - libcrux-kem 0.0.10
published: '2026-09-28'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T08:30:02.862241231Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/RUSTSEC-2026-0330'
references:
  - url: 'https://crates.io/crates/libcrux-kem'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0330.html'
  - url: 'https://github.com/celabshq/libcrux/pull/1595'
tags:
  - osv
  - rust
ingestedAt: '2026-10-08T07:34:51.739Z'
---

## Overview

For a hybrid KEM public key of type `PublicKey::WingKemDraft06` or `PublicKey::X25519MlKem768Draft06`, the `PublicKey::encapsulate_derand` function would panic in an indexing operation on a seed input of length shorter than 32 bytes.

# Impact

Applications encapsulating with an attacker controlled seed value could be made to panic. Since the encapsulation seed should be considered a secret of the encapsulating party for the KEM to remain secure, an application should never take the seed value from a potentially attacker controlled source.

# Mitigation

With release of version `0.0.10` of `libcrux-kem` this bug has been fixed and the serialization functions return `InvalidPrivateKey` and `InvalidPublicKey` errors on invalid input buffer lengths.

We recommend users upgrade to `libcrux-kem` version `0.0.10`.

## Affected packages

- `libcrux-kem >= 0.0.0-0, < 0.0.10`

## Remediation

Upgrade to a patched release:

- `libcrux-kem 0.0.10`