CVE-2026-39421: CWE-693: Protection Mechanism Failure in 1Panel-dev MaxKB
MaxKB versions 2. 7. 1 and below contain a sandbox escape vulnerability in the ToolExecutor component. An authenticated user with workspace privileges can bypass the LD_PRELOAD-based sandbox by using Python's ctypes library to make direct kernel system calls, leading to arbitrary code execution. This allows potential full network exfiltration and container compromise. The vulnerability arises because the sandbox blocks mprotect calls to prevent executable memory allocations but does not block pkey_mprotect, which can be abused. The issue is fixed in version 2. 8. 0.
AI Analysis
Technical Summary
CVE-2026-39421 is a sandbox escape vulnerability in the ToolExecutor component of MaxKB (versions prior to 2.8.0). The sandbox relies on LD_PRELOAD to intercept critical system functions and prevent executable memory allocations via mprotect. However, it fails to block pkey_mprotect, allowing an authenticated attacker with workspace privileges to bypass these restrictions by invoking raw kernel system calls through Python's ctypes library. This leads to arbitrary code execution, enabling full network exfiltration and container compromise. The vulnerability is classified under CWE-693 (Protection Mechanism Failure) and CWE-94 (Improper Control of Generation of Code).
Potential Impact
An authenticated attacker with workspace privileges can escape the sandbox environment, execute arbitrary code at the kernel level, and potentially exfiltrate data over the network or compromise the container hosting MaxKB. This undermines the intended isolation and security controls of the sandbox, increasing the risk of broader system compromise.
Mitigation Recommendations
This vulnerability has been fixed in MaxKB version 2.8.0. Users should upgrade to version 2.8.0 or later to remediate this issue. No other vendor advisory or patch information is provided, so patch status beyond this version is not confirmed. Until upgraded, restrict workspace privileges to trusted users only.
CVE-2026-39421: CWE-693: Protection Mechanism Failure in 1Panel-dev MaxKB
Description
MaxKB versions 2. 7. 1 and below contain a sandbox escape vulnerability in the ToolExecutor component. An authenticated user with workspace privileges can bypass the LD_PRELOAD-based sandbox by using Python's ctypes library to make direct kernel system calls, leading to arbitrary code execution. This allows potential full network exfiltration and container compromise. The vulnerability arises because the sandbox blocks mprotect calls to prevent executable memory allocations but does not block pkey_mprotect, which can be abused. The issue is fixed in version 2. 8. 0.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-39421 is a sandbox escape vulnerability in the ToolExecutor component of MaxKB (versions prior to 2.8.0). The sandbox relies on LD_PRELOAD to intercept critical system functions and prevent executable memory allocations via mprotect. However, it fails to block pkey_mprotect, allowing an authenticated attacker with workspace privileges to bypass these restrictions by invoking raw kernel system calls through Python's ctypes library. This leads to arbitrary code execution, enabling full network exfiltration and container compromise. The vulnerability is classified under CWE-693 (Protection Mechanism Failure) and CWE-94 (Improper Control of Generation of Code).
Potential Impact
An authenticated attacker with workspace privileges can escape the sandbox environment, execute arbitrary code at the kernel level, and potentially exfiltrate data over the network or compromise the container hosting MaxKB. This undermines the intended isolation and security controls of the sandbox, increasing the risk of broader system compromise.
Mitigation Recommendations
This vulnerability has been fixed in MaxKB version 2.8.0. Users should upgrade to version 2.8.0 or later to remediate this issue. No other vendor advisory or patch information is provided, so patch status beyond this version is not confirmed. Until upgraded, restrict workspace privileges to trusted users only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-07T00:23:30.595Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69dd958882d89c981f9c5825
Added to database: 4/14/2026, 1:16:56 AM
Last enriched: 4/14/2026, 1:32:14 AM
Last updated: 4/14/2026, 3:25:47 AM
Views: 3
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