MaxKB: SSRF via sandbox network hook bypass
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, sandbox network protection can be bypassed by using socket.sendto() with the MSG_FASTOPEN flag. This allows authenticated user with tool-editing permissions to reach internal services that are explicitly blocked by the sandbox's banned hosts configuration. MaxKB's sandbox uses LD_PRELOAD to hook the connect() function and block connections to banned IPs, but Linux's sendto() with the MSG_FASTOPEN flag can establish TCP connections directly through the kernel without ever calling connect(), completely bypassing the IP validation. Although sendto is listed in the syscall() wrapper, this is ineffective because glibc invokes the kernel syscall directly rather than routing through the hooked syscall() function. This issue has been fixed in version 2.8.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| 1Panel-dev | MaxKB | before 2.8.0 | 2.8.0 | Patch available | CNA |
- MaxKB Vendor1Panel-dev Affected before 2.8.0 Fixed in 2.8.0 Patch available CNA
Remediation
- Fix · CNA MaxKB (1Panel-dev) Fixed in 2.8.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-39418
References
More 1Panel-dev vulnerabilities
- TI-2023-08712 KubePi's Hardcoded Jwtsigkeys allows malicious actor to login with a forged JWT token CVSS 3.1CRITICAL 9.8
- TI-2023-08729 KubeOperator is vulnerable to unauthorized access to system API CVSS 3.1CRITICAL 9.8
- TI-2026-54047 MaxKB: Prompt-injectable agent can lead to command execution CVSS 3.1CRITICAL 10.0
- TI-2025-43180 CordysCRM 1.4.1 is vulnerable to SQL Injection in the employee list query interface… CVSS 3.1CRITICAL 9.8
- TI-2024-27040 Arbitrary File Read in Ansible Playbooks in Jumpserver CVSS 3.1CRITICAL 10.0
- TI-2024-26801 a sqlinjection in 1Panel CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences