CVE-2026-39419
MaxKB: Sandbox Result Validation Bypass via Tool Output Spoofing
CVSS Score
3.1
EPSS Score
0.0%
EPSS Percentile
14th
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.
| CWE | CWE-74 CWE-693 CWE-290 |
| Vendor | 1panel-dev |
| Product | maxkb |
| Published | Apr 14, 2026 |
| Last Updated | Apr 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
1Panel-dev / MaxKB
< 2.8.0