Marimo RCE Flaw Lets Hackers Steal AWS Credentials and Pivot to Bastion Host in 8 Seconds
Attacker exploited unauthenticated marimo WebSocket RCE CVE-2026-39987 to steal AWS credentials and SSH into a bastion host in eight seconds.
Sysdig Threat Research Team documented a real intrusion exploiting CVE-2026-39987 in marimo (versions up to 0.20.4, fixed in 0.23.0), where the unauthenticated /terminal/ws WebSocket endpoint exposed an interactive shell. Within eight seconds the attacker pulled AWS credentials from Redis, extracted an SSH private key from AWS Secrets Manager via Boto3, and authenticated to a bastion host; over nine hours the operator ran 850+ commands using a staged custom Python toolkit. Blocked EC2 Instance Connect attempts (SendSSHPublicKey to placeholder instance i-0000000000000000) provide a high-confidence detection signal.
⚡ Weekly Recap: VMware Exploits, Windows 0-Day, MCP Attacks, Browser Hijacks and More
Weekly recap: suspected China-nexus APT exploited VMware vCenter CVE-2026-59310, Lazarus used Windows zero-day CVE-2026-68820, and macOS flaw dropped Monero miners.
The week's top stories included a suspected China-nexus APT exploiting VMware vCenter CVE-2026-59310 (CVSS 9.8), a directory-traversal flaw enabling arbitrary code execution, with backdoors, reverse SSH and Babuk-derived ransomware deployed, per QUIRSO. NCSC-NL reported active exploitation of macOS Screen Sharing flaw CVE-2026-65400 (CVSS 9.8) to install Monero miners on systems with port 5900 exposed. Lazarus Group exploited Windows zero-day CVE-2026-68820 (CVSS 7.0) in Operation Dream Job, delivering ForestTiger and Troy backdoors to defense and aerospace targets. GeoServer patched a critical SQL injection flaw exploited within hours of disclosure, and Jamf analyzed the new Amnesia Stealer for macOS with live browser control.