How severe is CVE-2026-39417?

CVE-2026-39417 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-39417 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39417?

CVE-2026-39417 affects Maxkb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39417?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-39417 have an EU (EUVD) identifier?

Yes. CVE-2026-39417 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22162.

When was CVE-2026-39417 published?

CVE-2026-39417 was published on 2026-04-14 and last updated on 2026-06-17.

CVE-2026-39417

CVE-2026-39417 is a medium-severity vulnerability in Maxkb with a CVSS 3.x base score of 4.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 4.6)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-22162
Weakness: CWE-20
Affected product: Maxkb
Published: 2026-04-14
Last modified: 2026-06-17

Description

MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain an incomplete fix for CVE-2025-53928, where a Remote Code Execution vulnerability still exists in the MCP node of the workflow engine. MaxKB only restricts the referencing code path (loading MCP config from the database). The else branch, responsible for loading mcp_servers directly from user-supplied JSON remains completely unpatched. Since mcp_source is an optional field (required=False), an attacker can simply omit it or set it to any non-referencing value to bypass the fix. By calling the workflow creation API directly with a crafted JSON payload, an attacker can inject a complete MCP node configuration with stdio transport, arbitrary command, and args — achieving RCE when the workflow is triggered via chat. This issue has been fixed in version 2.8.0.

Frequently asked questions

What is CVE-2026-39417?: MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain an incomplete fix for CVE-2025-53928, where a Remote Code Execution vulnerability still exists in the MCP node of the workflow engine. MaxKB only restricts the referencing code path (loading MCP config from the database). The else branch, responsible for loading mcp_servers directly from user-supplied JSON remains completely unpatched. Since mcp_source is an optional field (required=False), an attacker can simply omit it or set it to any non-referencing value to bypass the fix. By calling the workflow creation API directly with a crafted JSON payload, an attacker can inject a complete MCP node configuration with stdio transport, arbitrary command, and args — achieving RCE when the workflow is triggered via chat. This issue has been fixed in version 2.8.0.
How severe is CVE-2026-39417?: CVE-2026-39417 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-39417 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39417?: CVE-2026-39417 affects Maxkb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39417?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-39417 have an EU (EUVD) identifier?: Yes. CVE-2026-39417 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22162.
When was CVE-2026-39417 published?: CVE-2026-39417 was published on 2026-04-14 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:maxkb:maxkb:*:*:*:*:-:*:*:*

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