CVE-2021-23663

CVE-2021-23663 is a critical prototype pollution vulnerability affecting all versions of the 'sey' package, allowing attackers to manipulate object prototypes via the deepmerge() function. With a CVSS score of 9.8, it presents a severe risk due to its network-based attack vector, low complexity, and potential for complete compromise of confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community discussion, indicating awareness among security researchers.