1Panel-dev MaxKB up to 2.7.x ToolExecutor sandbox.so LD_PRELOAD protection mechanism

Summaryinfo

A vulnerability classified as critical has been found in 1Panel-dev MaxKB up to 2.7.x. This impacts an unknown function of the file sandbox.so of the component ToolExecutor. This manipulation of the argument LD_PRELOAD causes protection mechanism. This vulnerability appears as CVE-2026-39421. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in 1Panel-dev MaxKB up to 2.7.x and classified as critical. Affected by this vulnerability is some unknown processing of the file sandbox.so of the component ToolExecutor. The manipulation of the argument LD_PRELOAD with an unknown input leads to a protection mechanism vulnerability. The CWE definition for the vulnerability is CWE-693. The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-39421 since 04/07/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 2.8.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 479701a4d2e6059506bad0057a66bed91abb5aef is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• 1Panel-dev

Name

• MaxKB

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7

License

• open-source

Website

• Product: https://github.com/1Panel-dev/MaxKB/

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