CVE-2026-31669 — AI Deep Analysis Summary

🚨 **Essence**: A critical memory management flaw in the Linux Kernel's MPTCP subsystem. <br>💥 **Consequences**: Improper socket allocation leads to **Use-After-Free (UAF)** vulnerabilities.…

🔍 **Root Cause**: During MPTCP subflow initialization, the system incorrectly copies an **unregistered TCPv6 protocol**.…

🌍 **Affected**: All versions of the **Linux Kernel** (maintained by the Linux Foundation). <br>📦 **Component**: Specifically the **MPTCP** (Multipath TCP) implementation and its subflow initialization logic.

👑 **Privileges**: Attackers can achieve **Full Kernel Privileges**. <br>📂 **Data**: Complete **Confidentiality, Integrity, and Availability** loss (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).…

⚡ **Threshold**: **Extremely Low**. <br>🔓 **Auth**: No authentication required (PR:N). <br>🌐 **Network**: Remote exploitation possible (AV:N). <br>👤 **User Interaction**: None needed (UI:N).…

🚫 **Public Exploit**: **No** public PoC or wild exploitation detected yet (POCs list is empty).…

🔎 **Self-Check**: <br>1. Verify if your system uses **MPTCP** functionality. <br>2. Check kernel version against the release date (April 2026). <br>3.…

✅ **Fixed**: **Yes**. Official patches have been released by the Linux Kernel Stable team. <br>🔗 **Evidence**: Multiple stable commits (e.g., `3fd6547f`, `b313e903`) address this issue.…

🛡️ **Workaround**: If patching is impossible immediately: <br>1. **Disable MPTCP** if not strictly required for your network stack. <br>2. Apply strict **network segmentation** to limit exposure. <br>3.…

🔥 **Urgency**: **CRITICAL / IMMEDIATE ACTION REQUIRED**. <br>📉 **Priority**: P1. With Remote, Low Complexity, and High Impact, this is a top-tier threat.…