4.0.3.1

2026 Aug 3

• Fixed security vulnerability: seed buffer aliasing with caller-owned bytes objects.
  • compute_signing_public_key() and signature_sign() (32-byte
    compatibility paths) and elligator_key_pair() passed the caller's
    immutable Python bytes object as Monocypher's mutable seed buffer.
    Monocypher deliberately wipes that seed, so a successful call zeroed
    the caller's object and all of its aliases. Reusing the same object
    then silently derived keys or signed under the publicly reproducible
    all-zero seed.
  • These functions now pass a private seed copy, which Monocypher wipes.
    The caller's object is never modified. Callers who also want their
    own seed object destroyed can explicitly call wipe().
  • Thank you to @geostergiop who reported this issue.
• Fixed setup.py to indicate Python 3.10 was dropped.