Hackers Exploit GitHub Copilot Flaw to Exfiltrate Sensitive Data

CamoLeak (CVE-2025-59145) was a critical prompt-injection vulnerability in GitHub Copilot Chat that allowed attackers to hide malicious instructions in invisible markdown comments within pull requests; Copilot ingested these hidden prompts, searched repositories for secrets, encoded results, and exfiltrated them by requesting attacker-controlled images through GitHub’s Camo image proxy, bypassing CSP and egress controls. The flaw enabled theft of source code and secrets without running malicious code, was publicly disclosed in October 2025 after GitHub patched it in August 2025, and highlights broader risks when AI assistants have deep access to private systems.