Critical Chainlit Session Hijack and OpenCTI SSRF Expose Internal Access

Two newly disclosed vulnerabilities affect widely used security and AI-adjacent platforms. Chainlit versions earlier than 2.10.1 are vulnerable to CVE-2026-56104, a critical flaw in WebSocket session restoration that lets an unauthenticated attacker supply a valid sessionId and inherit an authenticated user’s session without ownership verification. The issue can allow attackers to assume victim roles and permissions, invoke tools without authorization, and access data available only to the compromised user. The published guidance is to upgrade to Chainlit 2.10.1 or later and ensure session restoration enforces ownership checks.

OpenCTI is also affected by CVE-2026-21887, a server-side request forgery vulnerability in its data ingestion component that allows an authenticated attacker to force the platform to fetch attacker-controlled URLs. Because OpenCTI often runs as a trusted internal node in security operations environments, the flaw can be used to reach internal services, bypass perimeter controls, and in cloud deployments query the instance metadata service at 169.254.169.254 to obtain temporary AWS IAM credentials, potentially enabling broader infrastructure compromise. The issue was scored CVSS 7.7, and remediation centers on validating outbound destinations and blocking requests to private and link-local address ranges.