CVE-2026-39421

HIGH
MEDIUM Priority: 0.02 BB Relevance: 65/100
Published: 2026-04-14 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Changed
C: Low
I: Low
A: Low

Description

MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a sandbox escape vulnerability in the ToolExecutor component. By leveraging Python's ctypes library to execute raw system calls, an authenticated attacker with workspace privileges can bypass the LD_PRELOAD-based sandbox.so module to achieve arbitrary code execution via direct kernel system calls, enabling full network exfiltration and container compromise. The library intercepts critical standard system functions such as execve, system, connect, and open. It also intercepts mprotect to prevent PROT_EXEC (executable memory) allocations within the sandboxed Python processes, but pkey_mprotect is not blocked. This issue has been fixed in version 2.8.0.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
maxkb maxkb < 2.8.0

Bug Bounty Relevance

65 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

7.4 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

EPSS — Exploitation Probability

0.26%
Raw Score 0.002640
Percentile 18.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00264
2026-10-28
0.00264

Intelligence Sources

nvd ref →