OpenZeppelin Contracts is a library for secure smart contract development. The functions "ECDSA.recover" and "ECDSA.tryRecover" are vulnerable to a kind of signature malleability due to accepting EIP-2098 compact signatures in addition to the traditional 65 byte signature format. This is only an issue for the functions that take a single "bytes" argument, and not the functions that take "r, v, s" or "r, vs" as separate arguments. The potentially affected contracts are those that implement signature reuse or replay protection by marking the signature itself as used rather than the signed message or a nonce included in it. A user may take a signature that has already been submitted, submit it again in a different form, and bypass this protection. The issue has been patched in 4.7.3.