VulnerabilityAnalyzed

CVE-2026-39421

Versions 2.7.1 and below contain a sandbox escape vulnerability in the ToolExecutor component.

HIGH 7.4EPSS 0.26%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.4 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
EPSS: 0.26% probability · 18th percentile
CISA KEV: Not listed
Weakness: CWE-94, CWE-693
Affected: maxkb/maxkb
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.