Vulnerability · Published Apr 14, 2026 · Assigned by GitHub_M

CVE-2026-39421MaxKB: Sandbox escape via ctypes and unhooked SYS_pkey_mprotect

Medium 6.3

In plain English

A medium-severity code injection in MaxKB from 1Panel-dev. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).

Severity (CVSS 3.1)6.3Medium

Exploit odds (30 days)0.3%top 81.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
1Panel-dev	MaxKB	< 2.8.0

Weakness: CWE-693, CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

References

https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-9c6w-j7w5-3gf7 x_refsource_CONFIRM
https://github.com/1Panel-dev/MaxKB/commit/479701a4d2e6059506bad0057a66bed91abb5aef x_refsource_MISC
https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0 x_refsource_MISC