Bitcoin Core developers have issued a new high-severity warning that one in six Bitcoin nodes has a software vulnerability. Specifically, all software below Bitcoin Core version 24.0.1 is at risk. According to Bitnodes' monitoring estimates, the denial of service vulnerability affects approximately 3,330 of the 19,200 self-proclaimed user agents of accessible Bitcoin full nodes. The developers fixed the vulnerability in Bitcoin Core pull request (PR) number 25717 and merged it into production with the release of v24.0.1 on December 12, 2022. The current Bitcoin Core node software version (now 27.1) contains fixes for this and other vulnerabilities. Although the vulnerability is quite serious, there are few known attacks that exploit it in the public record. Since the cost of generating and broadcasting a block header chain to perform a denial of service attack is quite high, the vulnerability has little financial benefit to the attacker. (Protos)