Exploited vulnerabilities / CVE-2026-39987
Confirmed exploited · remote code execution · MarimoCVE-2026-39987
Marimo remote code execution, confirmed exploited in the wild.
Marimo contains an pre-authorization remote code execution vulnerability, allowing an unauthenticated attacked to shell access and execute arbitrary system commands.
| CISA's name for it | Marimo Remote Code Execution Vulnerability |
|---|---|
| Vendor and product | Marimo · Marimo |
| Type | remote code execution · CWE-306 |
| Exploited | Confirmed by CISA listed 23 April 2026 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 7 May 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | github.com ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Patch to the fixed version the vendor names, today if the product faces the internet.
Until it is patched, take the affected service off the internet or put it behind a VPN or allow-list.
Look for signs it was already used: new accounts, web shells, unexpected processes and outbound connections since the date it was listed.
| CISA's 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. |
|---|
Know before someone else finds it
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CVE-2026-39987 in short
Is CVE-2026-39987 being exploited?
Yes. CISA added CVE-2026-39987 to its Known Exploited Vulnerabilities catalogue on 23 April 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-39987?
US federal agencies must remediate it by 7 May 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-39987 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 100%, the 99th percentile of every CVE it scores.
How do I fix CVE-2026-39987?
Patch to the fixed version the vendor names, today if the product faces the internet. Until it is patched, take the affected service off the internet or put it behind a VPN or allow-list. Look for signs it was already used: new accounts, web shells, unexpected processes and outbound connections since the date it was listed.
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.