Hackers Exploit Ollama Model Uploads to Leak Server Data

A critical, unpatched vulnerability (CVE-2026-5757) in Ollama’s GGUF model quantization engine allows unauthenticated attackers to upload malicious model files that trigger an out-of-bounds memory read and exfiltrate sensitive heap data (e.g., API keys, user data). The flaw was discovered by Jeremy Brown, no vendor patch is available as of late April 2026, and immediate mitigations—disabling model uploads, isolating deployments, and restricting model sources—are recommended.