CVE-2026-39417 1Panel-dev CVE debrief

Who should care

Defenders managing MaxKB deployments, especially those using versions 2.7.1 or lower, should assess exposure and prioritize verification and remediation efforts. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Defenders should also plan vendor-supported updates or mitigations through normal change control where exposure is confirmed and review compensating controls for exposed

Why it matters

CVE-2026-39417 is a Remote Code Execution vulnerability in MaxKB, allowing attackers to inject MCP node configurations via crafted JSON payloads. Defenders should prioritize verifying exposure, especially in versions 2.7.1 and lower, and assess the feasibility of injecting MCP node configurations through workflow creation APIs.

• Potential Remote Code Execution
• Verification of exposure required
• Remediation priority for versions 2.7.1 and lower
• Monitoring for suspicious workflow triggers

Technical summary

CVE-2026-39417 is an RCE vulnerability in MaxKB versions 2.7.1 and lower. The issue arises from an incomplete fix for CVE-2025-53928, allowing attackers to inject MCP node configurations via crafted JSON payloads in the workflow creation API, potentially leading to RCE when workflows are triggered. The vulnerability is caused by the incomplete fix that only restricts referencing code paths from the database, leaving the direct loading of MCP servers from user-supplied JSON unpatched. This allows attackers to bypass the fix by omitting or setting a non-referencing value for the mcp_source field.

Defensive priority

Defenders should prioritize verifying exposure in MaxKB deployments, especially those using versions 2.7.1 or lower, and assess the feasibility of injecting MCP node configurations through workflow creation APIs.

Recommended defensive actions

• Verify MaxKB version and exposure to CVE-2026-39417
• Restrict access to workflow creation APIs
• Monitor for suspicious workflow triggers
• Update to version 2.8.0 or later
• Review compensating controls for exposed systems
• Track exceptions and retest remediated assets
• Check relevant monitoring, detection, and logs for exposed assets

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, affected versions, and fixed version 2.8.0. Vendor advisories and patch notes are available on GitHub. The vulnerability was publicly disclosed on 2026-04-14 and has been remediated in version 2.8.0. Defenders should verify exposure, especially in versions 2.7.1 and lower, and assess the feasibility of injecting MCP node configurations through workflow creation APIs.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.