CVE-2026-39421

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Source
https://cve.org/CVERecord?id=CVE-2026-39421
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39421.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-39421
Aliases
  • GHSA-9c6w-j7w5-3gf7
Published
2026-04-14T00:17:10.279Z
Modified
2026-08-12T16:25:05.223001Z
Severity
  • 6.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L CVSS Calculator
Summary
MaxKB: Sandbox escape via ctypes and unhooked SYS_pkey_mprotect
Details

MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a sandbox escape vulnerability in the ToolExecutor component. By leveraging Python's ctypes library to execute raw system calls, an authenticated attacker with workspace privileges can bypass the LDPRELOAD-based sandbox.so module to achieve arbitrary code execution via direct kernel system calls, enabling full network exfiltration and container compromise. The library intercepts critical standard system functions such as execve, system, connect, and open. It also intercepts mprotect to prevent PROTEXEC (executable memory) allocations within the sandboxed Python processes, but pkey_mprotect is not blocked. This issue has been fixed in version 2.8.0.

Database specific 
{
    "cwe_ids": [
        "CWE-693",
        "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39421.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/1panel-dev/maxkb

Affected ranges

Type
GIT
Repo
https://github.com/1panel-dev/maxkb
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
f0a73da5d9ee22e6374dabd4da1081569659530c
Fixed
479701a4d2e6059506bad0057a66bed91abb5aef
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:maxkb:maxkb:*:*:*:*:-:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.8.0"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.9.0
v0.9.1
v1.*
v1.0.0
v1.0.1
v1.1.0
v1.1.1
v1.1.2
v1.1.3
v1.10.0-lts
v1.10.1-lts
v1.10.2-lts
v1.10.3-lts
v1.10.4-lts
v1.2.0
v1.2.1
v1.3.0
v1.4.0
v1.5.0
v1.6.0
v1.6.1
v1.7.0
v1.9.0
v2.*
v2.0.0
v2.0.1
v2.0.2
v2.1.0
v2.2.0
v2.3.0
v2.4.0
v2.5.0
v2.6.0
v2.6.1
v2.7.0

Database specific

vanir_signatures 
[
    {
        "target": {
            "file": "installer/sandbox.c"
        },
        "id": "CVE-2026-39421-4c2d67cb",
        "signature_type": "Line",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
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                "215899905544571371363346647654910847672",
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                "273379757579468313691832175491861274907",
                "214540822084922879584728478775220403372",
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                "77003270660451475864336487078127752067",
                "101039684633117576466355377556765829980",
                "72870142656461788339807606966927120293",
                "185794847705964794824883988556701706994",
                "233525793223420118595944218215480940606",
                "324700793946917739298221818067695959491",
                "326697774877630540101510810603873949316",
                "57540359630194425438145503802790207801",
                "317667225488989083412705543232876221080",
                "153390035076029355573678921362963754837"
            ]
        },
        "signature_version": "v1",
        "source": "https://github.com/1panel-dev/maxkb/commit/479701a4d2e6059506bad0057a66bed91abb5aef",
        "deprecated": false
    },
    {
        "target": {
            "function": "syscall",
            "file": "installer/sandbox.c"
        },
        "id": "CVE-2026-39421-783d6d04",
        "signature_type": "Function",
        "digest": {
            "function_hash": "303805115504949174479967791286937650657",
            "length": 1407.0
        },
        "signature_version": "v1",
        "source": "https://github.com/1panel-dev/maxkb/commit/479701a4d2e6059506bad0057a66bed91abb5aef",
        "deprecated": false
    },
    {
        "target": {
            "function": "load_sandbox_config",
            "file": "installer/sandbox.c"
        },
        "id": "CVE-2026-39421-b55c83ec",
        "signature_type": "Function",
        "digest": {
            "function_hash": "182974900247231853443799271901822692160",
            "length": 1891.0
        },
        "signature_version": "v1",
        "source": "https://github.com/1panel-dev/maxkb/commit/479701a4d2e6059506bad0057a66bed91abb5aef",
        "deprecated": false
    },
    {
        "target": {
            "function": "is_in_allow_dl_paths",
            "file": "installer/sandbox.c"
        },
        "id": "CVE-2026-39421-f17083ea",
        "signature_type": "Function",
        "digest": {
            "function_hash": "141367552048969568835758199726554614489",
            "length": 756.0
        },
        "signature_version": "v1",
        "source": "https://github.com/1panel-dev/maxkb/commit/479701a4d2e6059506bad0057a66bed91abb5aef",
        "deprecated": false
    }
]
vanir_signatures_modified 
"2026-08-12T16:25:05Z"
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39421.json"