CVE-2025-68291

CVE-2025-68291 addresses a divide-by-zero vulnerability in the Linux kernel's Multipath TCP (MPTCP) implementation. Specifically, the mptcp_do_fastclose() function failed to initialize rcv_mss before calling tcp_send_active_reset(), leading to a system crash. This issue affects Linux kernel versions utilizing MPTCP. The vulnerability has a low attack complexity, as it can be triggered by an MPTCP socket, potentially leading to a denial-of-service (system crash). While a CVSS score is not provided, the FAUCET Risk Score of 7/100 suggests a relatively low overall risk. There is no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this vulnerability. The issue was identified and reported by syzbot, a kernel fuzzer, indicating it was discovered through automated testing rather than in-the-wild attacks.