Is CVE-2026-39421 actively exploited?

No active exploitation of CVE-2026-39421 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39421 be exploited remotely?

Yes. CVE-2026-39421 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39421?

CVE-2026-39421 has a CVSS score of 7.4 (HIGH).

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HIGH

CVE-2026-39421

CWE-94Published: April 14, 2026· Updated: Apr 20, 2026

7.4

CVSS v3.1

EPSS:0.07%probability of exploitation in 30 daysPercentile:22.4th

Official 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.

NVD Source

Technical Analysis

CVE-2026-39421 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.