CVE-2026-39419 — MaxKB: Sandbox Result Validation Bypass via Tool Output Spoofing
MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, an authenticated user can bypass sandbox result validation and spoof tool execution results by …
Published: 2026-04-14 · CVSS: 3.1 · CVSS 3.1
MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, an authenticated user can bypass sandbox result validation and spoof tool execution results by exploiting Python frame introspection to read the wrapper's UUID from its bytecode constants, then writing a forged result directly to file descriptor 1 (bypassing stdout redirection). By calling sys.exit(0), the attacker terminates the wrapper before it prints the legitimate output, causing the MaxKB service to parse and trust the spoofed response as the genuine tool result. This issue has been fixed in version 2.8.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7