CVE-2026-39419 (GCVE-0-2026-39419)

Vulnerability from cvelistv5 – Published: 2026-04-14 01:03 – Updated: 2026-04-14 01:03
VLAI?
Title
MaxKB: Sandbox Result Validation Bypass via Tool Output Spoofing
Summary
MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, an authenticated user can bypass sandbox result validation and spoof tool execution results by exploiting Python frame introspection to read the wrapper's UUID from its bytecode constants, then writing a forged result directly to file descriptor 1 (bypassing stdout redirection). By calling sys.exit(0), the attacker terminates the wrapper before it prints the legitimate output, causing the MaxKB service to parse and trust the spoofed response as the genuine tool result. This issue has been fixed in version 2.8.0.
CWE
  • CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
  • CWE-693 - Protection Mechanism Failure
  • CWE-290 - Authentication Bypass by Spoofing
Assigner
Impacted products
Vendor Product Version
1Panel-dev MaxKB Affected: < 2.8.0
Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "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. In versions 2.7.1 and below, an authenticated user can bypass sandbox result validation and spoof tool execution results by exploiting Python frame introspection to read the wrapper\u0027s UUID from its bytecode constants, then writing a forged result directly to file descriptor 1 (bypassing stdout redirection). By calling sys.exit(0), the attacker terminates the wrapper before it prints the legitimate output, causing the MaxKB service to parse and trust the spoofed response as the genuine tool result. This issue has been fixed in version 2.8.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-74",
              "description": "CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component (\u0027Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-693",
              "description": "CWE-693: Protection Mechanism Failure",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290: Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-14T01:03:40.653Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-f3c8-p474-xwfv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-f3c8-p474-xwfv"
        },
        {
          "name": "https://github.com/1Panel-dev/MaxKB/commit/38c4cfecd065293ede0437f6fa76cf0116591d25",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/1Panel-dev/MaxKB/commit/38c4cfecd065293ede0437f6fa76cf0116591d25"
        },
        {
          "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-f3c8-p474-xwfv",
        "discovery": "UNKNOWN"
      },
      "title": "MaxKB: Sandbox Result Validation Bypass via Tool Output Spoofing"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39419",
    "datePublished": "2026-04-14T01:03:40.653Z",
    "dateReserved": "2026-04-07T00:23:30.595Z",
    "dateUpdated": "2026-04-14T01:03:40.653Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-39419\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-14T02:16:05.143\",\"lastModified\":\"2026-04-14T02:16:05.143\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, an authenticated user can bypass sandbox result validation and spoof tool execution results by exploiting Python frame introspection to read the wrapper\u0027s UUID from its bytecode constants, then writing a forged result directly to file descriptor 1 (bypassing stdout redirection). By calling sys.exit(0), the attacker terminates the wrapper before it prints the legitimate output, causing the MaxKB service to parse and trust the spoofed response as the genuine tool result. This issue has been fixed in version 2.8.0.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":3.1,\"baseSeverity\":\"LOW\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.6,\"impactScore\":1.4}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-74\"},{\"lang\":\"en\",\"value\":\"CWE-290\"},{\"lang\":\"en\",\"value\":\"CWE-693\"}]}],\"references\":[{\"url\":\"https://github.com/1Panel-dev/MaxKB/commit/38c4cfecd065293ede0437f6fa76cf0116591d25\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-f3c8-p474-xwfv\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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