Will Linux kernel MPTCP RCE vulnerability be added to CISA KEV by Dec 2026?

Security researchers at Anthropic disclosed a critical Linux kernel vulnerability in Multipath TCP (MPTCP) that allows unauthenticated attackers to remotely execute code as root on servers running MPTCP listeners. Given Anthropic's credibility and the exploit's nature, this vulnerability is likely to attract threat-actor attention and rapid exploitation. The question tracks whether CISA formally recognizes it as known exploited.

Resolution Criteria

CISA KEV Catalog entry for a CVE matching the MPTCP Linux kernel vulnerability described by Anthropic researchers. Source: official CISA KEV database or CISA security advisory naming the CVE.