Is CVE-2026-39418 actively exploited?

No active exploitation of CVE-2026-39418 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39418 be exploited remotely?

Yes. CVE-2026-39418 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39418?

CVE-2026-39418 has a CVSS score of 7.4 (HIGH).

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HIGH

CVE-2026-39418

CWE-918Published: April 14, 2026· Updated: Apr 20, 2026

7.4

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:7.7th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-39418 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.