Executive brief
JunoClaw is an AI platform that interacts with the Juno blockchain network. A security flaw was identified where sensitive cryptocurrency wallet recovery phrases (mnemonics) were transmitted in plain text during AI tool calls. This exposure allows anyone with access to communication logs, telemetry, or the network path between the AI provider and the platform to steal the credentials and gain full control over the associated blockchain assets.
Technical details
JunoClaw's Model Context Protocol (MCP) implementation for the Juno Network contained a design flaw where write-operation tools (such as send_tokens and execute_contract) required a 'mnemonic' string as a direct parameter. Because these parameters are part of the LLM tool-call JSON, the BIP-39 seed phrase was transmitted in cleartext and subsequently recorded in application logs, telemetry data, and intermediate transport layers between the LLM provider and the MCP process. An attacker with access to any of these data streams could recover the mnemonic and gain full unauthorized access to the user's wallet. The vulnerability was addressed by replacing the raw mnemonic parameter with an opaque 'wallet_id' handle and implementing an encrypted local wallet registry that uses AES-256-GCM to protect seeds at rest.
Affected products
- JunoClaw cosmos-mcp < 0.3.0
Timeline
- 2026-04-26: patched: Fixed in version 0.3.0 (v0.x.y-security-1)
- 2026-05-12: disclosed: CVE-2026-43992 published