AI Models Resize Photos and Open Door to Hacking

Researchers Show How AI Image Downscaling Can be an Attack Vector Rashmi Ramesh (rashmiramesh_) • August 22, 2025

It's easy to hide secret information inside a picture - secret agents and hackers have done it for millennia. Now security researchers have discovered a method to hide malicious instructions in a digital image that appear only when the files are automatically resized by AI models.

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The new class of attacks uses image scaling vulnerabilities to conduct prompt injections against AI systems, extracting user data from production platforms such as Google's Gemini CLI, said Trail of Bits. The technique exploits the common practice of downscaling large images before processing, creating opportunities for attackers to embed instructions that are invisible at full resolution but show up when the image is compressed.

The attack works by manipulating specific pixels in high-resolution images, so ...