DeepSeek Harness Flaw Let AI Agents Disable Their Own File Sandbox Without Approval

DeepSeek Harness Flaw Let AI Agents Disable Their Own File Sandbox Without Approval Swati KhandelwalSep 09, 2026Vulnerability / Artificial Intelligence A flaw in DeepSeek Harness, DeepSeek's open-source tool for running AI coding agents on a developer's machine, let a sandboxed agent turn off its own sandbox with a single command. The tool runs an agent's commands inside an operating-system sandbox, so that an agent working on untrusted files cannot write outside its workspace. The agent could remove that limit by calling the tool's own web interface on the same machine, and its commands would then run outside the sandbox without an approval prompt. It worked on a default installation until DeepSeek fixed the tool on August 27, and it required…