CVE-2026-42193 — Plunk: This allows an unauthenticated attacker to spoof SNS events to trigger workflow automations, unsubscribe
Plunk is an open-source email platform built on top of AWS SES. Prior to version 0.9.0, the /webhooks/sns endpoint accepts Amazon SNS notification payloads from unauthenticated requests without verifying the SNS signature, certificate, or topic ARN, meaning anyone can forge a valid-looking webhook request. This allows an unauthenticated attacker to spoof SNS events to trigger workflow automations, unsubscribe contacts, manipulate email delivery metrics, and potentially exhaus CVSSv3.1 9.1 (CRITICAL)