{"slug": "anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access", "title": "Anthropic AI model finds Linux kernel bug that leads to remote root access", "summary": "Anthropic disclosed a zero-click Linux kernel exploit, tracked as CVE-2026-98432, that lets an unauthenticated attacker execute arbitrary commands as root on servers running Multipath TCP (MPTCP) listeners, using an unreleased Claude research model. Anthropic said its proof of concept took approximately 53 minutes to go from initial kernel memory leak to root-level command execution, chaining a race-condition use-after-free in IPv4 TCP connection establishment with KASLR bypass and control-flow hijacking. The flaw carries a critical severity score of 9.8 and affects eight Linux kernel branches back to version 4.4, with fixes in 5.10.272, 5.15.223, 6.6.159, 6.1.190, 6.12.113, 6.18.56, 7.2.10 and 7.3-rc7, though Ubuntu and Red Hat Enterprise Linux had yet to ship patched kernels as of October 30.", "body_md": "Linux servers running Multipath TCP (MPTCP) could be vulnerable to remote code execution through a flaw in the kernel’s networking stack.\n\nAnthropic has disclosed a zero-click exploit developed with an unreleased Claude research model that allows an unauthenticated attacker to execute arbitrary commands as root, without requiring any user interaction.\n\nTracked as [CVE-2026-98432](https://linuxcvetracker.com/cve/CVE-2026-98432/), the vulnerability is a race-condition-induced use-after-free (UAF) bug in the Linux kernel. Anthropic demonstrated how an attacker could exploit the flaw remotely to leak kernel memory, defeat Kernel Address Space Layout Randomization (KASLR), hijack kernel control flow, and ultimately execute an attacker-controlled shell command.\n\nThe research is part of Anthropic’s broader effort to evaluate AI models’ ability to discover and exploit vulnerabilities in widely deployed software. The company disclosed five exploit chains involving Chrome, Safari, Android, Windows, and Linux to demonstrate how its internal model could combine multiple weaknesses into functional attacks.\n\nAnthropic’s proof of concept for the [Linux exploit](https://www.csoonline.com/article/4236460/linux-kernel-gets-a-fix-for-a-flaw-that-enabled-attackers-to-escape-vms.html) took approximately 53 minutes to progress from the initial memory leak to successful root-level command execution, the company said in a [blog post](https://docs.kernel.org/networking/mptcp.html).\n\nAccording to a Linux kernel CVE [advisory](https://www.cve.org/CVERecord?id=CVE-2026-98432), the underlying flaw involves how Linux manages IP options during IPv4 [TCP](https://www.csoonline.com/article/574303/tcp-floods-are-again-the-leading-ddos-attack-vector.html) connection establishment. When a new connection is created, the kernel can transfer ownership of IP options from a pending connection request to the newly created socket without making a separate copy.\n\nThe problem arises when another CPU is simultaneously processing a retransmitted connection request and using those same options to construct a synchronize-acknowledge (SYNACK) response. If the child socket is freed before the second CPU finishes accessing the options, the kernel can end up reading memory that has already been released.\n\nThis creates a use-after-free condition. The upstream fix addresses the memory-management problem by deferring the release of the affected objects until after a read-copy-update (RCU) grace period, giving concurrent readers time to finish accessing them.\n\nThe flaw received a critical severity score of 9.8 and affects eight Linux kernel branches, dating back to version 4.4. Fixed releases include 5.10.272, 5.15.223, 6.6.159, 6.1.190, 6.12.113, 6.18.56, 7.2.10 and 7.3-rc7.\n\nFor users who obtain Linux through distributions such as Debian, Oracle Linux, SUSE, and Amazon Linux, fixed kernel packages are available for at least some releases. Ubuntu and Red Hat Enterprise Linux, however, had yet to release patched kernels as of October 30.\n\nAnthropic’s exploit specifically targets Linux servers running an [MPTCP](https://docs.kernel.org/networking/mptcp.html) listener. MPTCP extends conventional TCP by allowing a device to use multiple network interfaces simultaneously within a single connection. This enables bandwidth aggregation, improved network selection, and failover when one network path becomes unavailable.\n\nLinux implements MPTCP through its networking stack, but the protocol is opt-in: applications must explicitly request it when creating sockets, although mechanisms such as eBPF and other configuration techniques can also force applications to use it.\n\nAdministrators are advised to review their kernel versions, apply the relevant security updates, and assess whether their systems expose MPTCP listeners.", "url": "https://wpnews.pro/news/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access", "canonical_source": "https://www.csoonline.com/article/4242724/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access.html", "published_at": "2026-10-30 12:27:11+00:00", "updated_at": "2026-10-30 12:47:53.223717+00:00", "lang": "en", "topics": ["ai-safety", "artificial-intelligence", "large-language-models"], "entities": ["Anthropic", "Claude", "Linux", "Multipath TCP", "CVE-2026-98432", "Ubuntu", "Red Hat Enterprise Linux", "Debian"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access", "markdown": "https://wpnews.pro/news/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access.md", "text": "https://wpnews.pro/news/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access.txt", "jsonld": "https://wpnews.pro/news/anthropic-ai-model-finds-linux-kernel-bug-that-leads-to-remote-root-access.jsonld"}}