Auth bypass in Marimo-team Marimo
CVE-2026-39987
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 a…
Vulnerability class: Broken Authentication
EPSS: 0.807 (99.2th percentile) — read the EPSS interpretation.
Affected products
- Marimo-team Marimo — versions < 0.23.0
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
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.
Public proof-of-concept exploits
- M3PH1569/CVE-2026-39987-POC
- jenniferreire26/CVE-2026-39987
- HORKimhab/CVE-2026-39987
- 0xdeadroot/CVE-2026-39987-marimo-rce
- rootdirective-sec/CVE-2026-39987-Lab
- Dhiaelhak-Rached/CVE-2026-39987-lab-or-marimo-cve-lab
- h3raklez/CVE-2026-39987
- Nxploited/CVE-2026-39987
- keraattin/CVE-2026-39987
- mki9/CVE-2026-39987_exploit
References
- https://github.com/marimo-team/marimo/security/advisories/GHSA-2679-6mx9-h9xc (x_refsource_CONFIRM)
- https://github.com/marimo-team/marimo/pull/9098 (x_refsource_MISC)
- https://github.com/marimo-team/marimo/commit/c24d4806398f30be6b12acd6c60d1d7c68cfd12a (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-39987?
- CVE-2026-39987 is a vulnerability in Marimo-team Marimo, classified under Missing Authentication for Critical Function. Published 2026-04-09.
- Is CVE-2026-39987 known to be exploited?
- Yes. CVE-2026-39987 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-23), indicating it is being actively exploited. 12 public proof-of-concept repositories are indexed.