CVE-2026-39987
marimo-team marimo
Published 9 Apr 2026 · updated 17 Jun 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 23 Apr 2026, with a remediation deadline of 7 May 2026 for US federal agencies.
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description
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.
References
- github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a · Patch
- github.com/marimo-team/marimo/pull/9098 · Issue Tracking, Patch
- github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc · Exploit, Mitigation, Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39987 · US Government Resource
- www.sysdig.com/blog/marimo-oss-python-notebook-rce-from-disclosure-to-exploitation-in-under-10-hours · Exploit, Third Party Advisory