CVE-2026-100858: Heymrun Heym

Medium severity, CVSS 6.8. EPSS: 0.3% chance of exploitation in the next 30 days.

heym before 0.0.109 contains a server-side request forgery vulnerability in the Slack, Discord, and Crawler workflow nodes. These nodes issue HTTP requests to URLs taken from user-created credentials (webhook_url / flaresolverr_url) using an unguarded HTTP client, bypassing the SSRF egress guard that already protects the HTTP, WebSocket, and MCP nodes; the credential API validates only that the URL is non-empty. Any registered user can create a credential pointing at an internal address and execute a workflow, causing the backend to reach loopback, private, link-local, or cloud-metadata endpoints and return the full response body in the node output (non-blind SSRF).

Affected products

• Heymrun Heym: before 0.0.109 (fixed in 0.0.109)

Published 2026-09-27. Last modified 2026-09-30.