CVE-2026-39417 (GCVE-0-2026-39417)

Vulnerability from cvelistv5 – Published: 2026-04-14 00:03 – Updated: 2026-04-14 13:34
VLAI
Title
MaxKB: RCE via MCP stdio command injection in workflow engine
Summary
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.
Severity
4.6 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-14 13:33 UTC
CWE
  • CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
  • CWE-20 - Improper Input Validation
Assigner
GitHub_M CNA
References
Impacted products
Vendor Product Version
1Panel-dev MaxKB Affected: < 2.8.0
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-39417",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-14T13:33:54.884442Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-14T13:34:07.454Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "MaxKB",
          "vendor": "1Panel-dev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.8.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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 \u2014 achieving RCE when the workflow is triggered via chat. This issue has been fixed in version 2.8.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.6,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-78",
              "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-14T00:03:16.020Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-pw52-326g-r5xj",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-pw52-326g-r5xj"
        },
        {
          "name": "https://github.com/1Panel-dev/MaxKB/commit/50e96002ee5dca34c68d3d9333b64ea358c92304",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/1Panel-dev/MaxKB/commit/50e96002ee5dca34c68d3d9333b64ea358c92304"
        },
        {
          "name": "https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0"
        }
      ],
      "source": {
        "advisory": "GHSA-pw52-326g-r5xj",
        "discovery": "UNKNOWN"
      },
      "title": "MaxKB: RCE via MCP stdio command injection in workflow engine"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39417",
    "datePublished": "2026-04-14T00:03:16.020Z",
    "dateReserved": "2026-04-07T00:23:30.595Z",
    "dateUpdated": "2026-04-14T13:34:07.454Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-39417",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-04-14T13:33:54.884442Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-04-14T13:34:00.626Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "MaxKB",
              "vendor": "1Panel-dev",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003c 2.8.0"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "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 \u2014 achieving RCE when the workflow is triggered via chat. This issue has been fixed in version 2.8.0."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 4.6,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-78",
                  "description": "CWE-78: Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-20",
                  "description": "CWE-20: Improper Input Validation",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-04-14T00:03:16.020Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-pw52-326g-r5xj",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-pw52-326g-r5xj"
            },
            {
              "name": "https://github.com/1Panel-dev/MaxKB/commit/50e96002ee5dca34c68d3d9333b64ea358c92304",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/1Panel-dev/MaxKB/commit/50e96002ee5dca34c68d3d9333b64ea358c92304"
            },
            {
              "name": "https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0"
            }
          ],
          "source": {
            "advisory": "GHSA-pw52-326g-r5xj",
            "discovery": "UNKNOWN"
          },
          "title": "MaxKB: RCE via MCP stdio command injection in workflow engine"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-39417",
        "datePublished": "2026-04-14T00:03:16.020Z",
        "dateReserved": "2026-04-07T00:23:30.595Z",
        "dateUpdated": "2026-04-14T13:34:07.454Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.