Delimiter Injection Vulnerability in mistral.rs Product by EricLBuehler

CVE-2026-124028

What is CVE-2026-124028?

The mistral.rs software, specifically versions prior to 0.9.5, is susceptible to a delimiter injection vulnerability within the mistralrs-core module. This flaw permits malicious actors to inject arbitrary tool calls by embedding delimiters like </tool_call> into text that the model processes. When attackers gain control over documents, web pages, or tool outputs, they can manipulate parsers such as qwen-xml, gemma4, and reasoning to execute unwanted commands with provided arguments. This poses significant risks to systems reliant on the affected versions, leading to potential exploitation through unexpected tool calls.

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