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CVE-2026-107717PYSEC-2026-4202GHSA-HMQ2-7HP6-7CRH

Banks: User-controlled prompt input can be parsed as privileged chat messages

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.5.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.0, Banks Prompt.chat_messages() attempts to parse every line of rendered template output as ChatMessage JSON. When an application renders untrusted data and passes the returned ChatMessage objects to an LLM provider, attacker-controlled JSON can cross the prompt boundary and become a system, assistant, or tool message because ChatMessage.role accepts arbitrary strings. This can override application instructions, alter the intended prompt structure, or confuse downstream tool and message handling. This issue is fixed in version 2.5.0.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • masci banks

    fixed in 2.5.0

  • banksPyPI

    fixed in 2.5.0

References 4

GitHub · masci/banks