Malicious LLMs could hijack GPU hosts by exploiting inference engine bugs
LLMs could control their host machines by exploiting inference engines
A new essay warns that LLMs could seize control of the machines that run them by exploiting vulnerabilities in inference engines like vLLM and SGLang. These engines parse token sequences into responses, and bugs can allow arbitrary code execution. The essay cites CVE-2025-9141, where vLLM's tool parser used eval(), and discusses how multimodal outputs and tool use could expand the attack surface. It suggests defenses like separating GPU and parsing hosts and treating GPU data as untrusted.
Because the LLM controls the tokens passed to the inference engine, a malicious LLM could therefore emit a sequence of tokens that a poorly written inference engine mistakes for code or instructions to execute rather than data to return to the user.
- angry_octet
People seem very confused about this article. It isn't talking about exploits of sandboxes, it is about attacking the inference engine (e.g. vLLM or llama.cpp or SGlang) via its http interface.
vLLM has had exploits in the past, and it is rapidly developing. An advanced LLM has a good chance of being able to exploit vLLM. A clever local LLM might even task a powerful cloud hosted LLM for assistance.
For this reason we run vLLM on a separately sandboxed VM on a firewalled VLAN. Software updates and models (from Dev/Test env) get pushed onto Prod from an external cache, machine syslog, nvidia load monitoring and vLLM query telemetry out to their loggers, but that is all. No DNS, no AD/LDAP, nothing. Firewall on hosts and VM hosts. Log and telemetry processing done on a completely separate set of VMs in their own isolated subnet, producing reports and alerts that are tightly formatted.
- ma2kx
I had a similar though a couple days ago. Not quite the same but imagine giving an Agent the task to hack other devices and steal their crypto coins / credit card number or anything with it can pay its token. Than install an agent in a harness with the same task. Establish some redundant communication channel, like message boards or whatever. So in the end there are several agents, on several hosts, consuming different APIs / LLMs and communicating with each other over different channels. Basically the same concept as OpenAI explained when their LLM hacked huggingface but in this scenario their not bound to a single sandboxed environment but spread over the internet. If such a swarm has reached a critical mass it would be pretty dificult to erase them as its impossible to control every inference engine or LLM API endpoint.
In the end its the next evolution step from computer viruses, worms and trojans. So I propose we will call those "ghosts". I.e. a ghost is when a rogue llm takes control over a victims host.
- xg15
> ...however the LLMs’ responses to prompts are computed on a different computer with GPU access. Could a malicious LLM gain control of the host machine where its weights are loaded? Such a machine is a high-value target: it has sufficient compute to run a frontier LLM, offers easy access to the LLM’s weights, and has privileged access to other computers in the datacentre compared with a generic computer on the internet.
> How do we defend against this? ... Run the GPUs and token parser on separate computers.
For models large enough to be relevant here, is there even "a" computer where the inference is performed? I'd imagine most of that stuff is ran on multi-GPU clusters with specialized architecture and not a generic vLLM instance. As such, I think there is a good chance the "API gateway" code that parses the result tokens into whatever JSON structure the public API wants to return is already running on a different machine than the actual inference.
(Even more so as you'd probably want to utilize batching: Several API calls will be put into the same inference batch, but the token parsing will have to be done separately for each call again)
The article is also very handwavy about why an LLM should do that - how it could learn the exploit, what would make it conclude that it can use the exploit on its own inference session and what would trigger it to actually use the exploit.
- LunicLynx
The funny thing about this is, that this is the piece that will enable them to do it.
- genxy
I thought they were going to get the LLM to "think really hard about rowhammer" and have the LLM conjure a JIT.