Cline: Vulnerable To Data Exfiltration And How To Protect Your Data
Summary
Cline, a popular AI coding agent with over 2 million downloads, has a vulnerability that allows attackers to steal sensitive files like .env files (which store secret credentials) through prompt injection (tricking an AI by hiding instructions in its input) combined with markdown image rendering. When an attacker embeds malicious instructions in a file and asks Cline to analyze it, the tool automatically reads sensitive data and sends it to an untrusted domain by rendering an image, leaking the information without user permission.
Solution / Mitigation
The source recommends these explicit mitigations: (1) Do not render markdown images from untrusted domains, or ask for user confirmation before loading images from untrusted domains (similar to how VS Code/Copilot uses a trusted domain list). (2) Set 'Auto-approve' to disabled by default to limit which files can be exfiltrated. (3) Developers can partially protect themselves by disabling auto-execution of commands and requiring approval before reading files, though this only limits what information reaches the chat before exfiltration occurs.
Classification
Affected Vendors
Related Issues
CVE-2025-45150: Insecure permissions in LangChain-ChatGLM-Webui commit ef829 allows attackers to arbitrarily view and download sensitive
CVE-2025-54868: LibreChat is a ChatGPT clone with additional features. In versions 0.0.6 through 0.7.7-rc1, an exposed testing endpoint
Original source: https://embracethered.com/blog/posts/2025/cline-vulnerable-to-data-exfiltration/
First tracked: February 12, 2026 at 02:20 PM
Classified by LLM (prompt v3) · confidence: 92%