ThreatsDay: Adobe RCE, DNS Wallet Theft, NVIDIA Container Escape, Self-Healing Backdoor + 23 More · 2h Silent Lynx Exploits WinRAR Flaw to Deploy Reverse Shell in CIS Government Attacks · 5h NGINX Fixes 5 Flaws, Including Possible RCE and a TLS Bug That May Skip Client-Cert Checks · 8h Next.js Ships Out-of-Band Patch for Two Critical RCE Flaws in Caching and SVG Processing · 8h Drupal Patches Critical Core RCE Flaw with No-Login Path via Contributed Modules · 9h Vulnerability in Sparx Systems Enterprise Architect software · 9h Curl verhelpt 'high' RCE-kwetsbaarheid gevonden door Anthropic · 9h Vulnerabilities in Slican telephone exchanges · 10h Palo Alto Networks waarschuwt voor misbruik van beveiligingslek in firewalls · 13h Cisco meldt actief misbruik van kritiek lek in Secure Email Gateway · 14h ThreatsDay: Adobe RCE, DNS Wallet Theft, NVIDIA Container Escape, Self-Healing Backdoor + 23 More · 2h Silent Lynx Exploits WinRAR Flaw to Deploy Reverse Shell in CIS Government Attacks · 5h NGINX Fixes 5 Flaws, Including Possible RCE and a TLS Bug That May Skip Client-Cert Checks · 8h Next.js Ships Out-of-Band Patch for Two Critical RCE Flaws in Caching and SVG Processing · 8h Drupal Patches Critical Core RCE Flaw with No-Login Path via Contributed Modules · 9h Vulnerability in Sparx Systems Enterprise Architect software · 9h Curl verhelpt 'high' RCE-kwetsbaarheid gevonden door Anthropic · 9h Vulnerabilities in Slican telephone exchanges · 10h Palo Alto Networks waarschuwt voor misbruik van beveiligingslek in firewalls · 13h Cisco meldt actief misbruik van kritiek lek in Secure Email Gateway · 14h

ACyber Sentinel Security Assessment Team

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⚠️ Vulnerability Report

CVE-2026-90898

CRITICAL CVSS 9.8 CVSS 3.1 📌 Awaiting Analysis

CVE-2026-90898 - Bifrost unauthenticated remote code execution via MCP stdio client registration

Bifrost registers MCP clients through its management API. A stdio client is a command plus args. Bifrost starts that program in the gateway the moment the client is added. No MCP handshake required.

The default is governance.auth_config.is_enabled=false. Auth off means every caller is a local admin. One unauthenticated POST /api/mcp/client is enough to run a program as the Bifrost process user (appuser on the official image).

transports/v2.1.0 refuses an unauthenticated stdio registration with 403. transports/v2.0.0 still allows it.

Published: Sep 14, 2026 11:17

Last Modified: Sep 18, 2026 19:31