Prompt Hijacking Risks MCP-Based AI Workflows Exposed
⚠️ Security researchers warn that MCP-based AI workflows are vulnerable to "prompt hijacking" when MCP servers issue predictable or reused session IDs, allowing attackers to inject malicious prompts into active client sessions. JFrog demonstrated the issue in oatpp-mcp (CVE-2025-6515), where guessable session IDs could be harvested and reassigned to craft poisoned responses. Recommended mitigations include generating session IDs with cryptographically secure RNGs (≥128 bits of entropy) and having clients validate unpredictable event IDs.
