marimo is a reactive Python notebook. Prior to 0.23.0, Marimo has a Pre-Auth RCE vulnerability. The terminal WebSocket endpoint /terminal/ws lacks authentication validation, allowing an unauthenticated attacker to obtain a full PTY shell and execute arbitrary system commands. Unlike other WebSocket endpoints (e.g., /ws) that correctly call validate_auth() for authentication, the /terminal/ws endpoint only checks the running mode and platform support before accepting connections, completely skipping authentication verification. This vulnerability is fixed in 0.23.0.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39987.json",
"cwe_ids": [
"CWE-306"
],
"cna_assigner": "GitHub_M"
}{
"source": [
"CPE_RANGE",
"REFERENCES"
],
"cpe": "cpe:2.3:a:coreweave:marimo:*:*:*:*:*:python:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "0.23.0"
}
]
}