Stop trusting eMudhra-related certificates, Teku and Besu fix client vulnerabilities

Ethereum client Teku has released version 26.10.3, and Besu has released version 26.10.2. Both versions stop trusting certificates related to the Indian certificate authority eMudhra in their Docker images. Researchers previously found that, due to cryptographic flaws, the private keys of eight eMudhra intermediate certificate authorities could be derived. Teku stated that an attacker positioned between a validator and the service it connects to could impersonate that service and induce the validator to propose blocks that pay fees to the attacker's address; external signers face the highest forgery risk. Teku said that default mainnet nodes are not affected, and no exploitation of the vulnerability has been reported so far. Operators who run the client directly without using Docker need to update Java themselves; users still on Java 26 need to migrate to Java 25, which has reached end of life.