CVE-2026-45311: DeepSeek TUI: run_tests Tool Enables RCE via Malicious Repository Without Approval

The run_tests tool executes cargo test in the workspace with ApprovalRequirement::Auto, meaning it runs without any user approval prompt. The source code explicitly states this design choice:

fn approval_requirement(&self) -> ApprovalRequirement {
// Tests are encouraged, so avoid gating them behind approval.
ApprovalRequirement::Auto
}

cargo test compiles and executes arbitrary code: test binaries, build.rs build scripts, and proc macros. While auto-approving test execution is a deliberate design choice, it creates an inconsistency in the security boundary. However, in a malicious repository, test code can execute arbitrary shell commands, exfiltrate credentials, or establish persistence with zero approval.

The attack is amplified by AGENTS.md (auto-loaded into the system prompt), which can instruct the model to run tests proactively at session start.