Blockchain is a decentralized ecosystem, which is built to secure vital information. With the security of blockchain, there are still some security vulnerabilities that people are still building solutions on. These security vulnerabilities are weaknesses that are present in blockchain Some notable common security vulnerabilities are

Smart Contract Vulnerability is one of the human code errors. They are the existing smart contracts deployed on the blockchain which contain some security vulnerabilities such as bugs or loopholes where malicious actors can penetrate.

51% attack is another security vulnerability that is present on the blockchain. In the case where a blockchain ecosystem chooses to use proof work. If some particular group decides to have control of the 50% of the network ecosystem. With that control, such a blockchain can't be seen as a decentralized blockchain since it is controlled by a set of individuals.

Sybil Attacks: Malicious actors on the node are looking for a way to hack into the network or dominate the ecosystem. They create fake multiple users to gain control of the blockchain network.

Private Key vulnerability: A private key is used to secure a user account from being manipulated. When a user loses the private key, such a user can't access the account. Malicious actors can steal private keys to have access to funds inside the wallet.

To prevent these security vulnerabilities, constant solutions should be built for different networks to enhance a secure environment for blockchain. For every smart contract deployed on the blockchain network, there must be a thorough security check that malicious actors can not penetrate. Constant updates on cryptography should be built to ensure secure cryptographic algorithms for hashing. Constant consensus mechanism evaluation to prevent users from having multiple accounts or some entity having control over the blockchain network