Executive brief
Sipeed PicoClaw is an AI assistant framework designed for low-power hardware. A security flaw in its LINE messaging integration allows an attacker to resend previously captured messages, tricking the system into processing them multiple times. This can lead to duplicate automated actions, repeated financial costs for AI processing, and inconsistent data in connected workflows.
Technical details
An authentication bypass by capture-replay exists in the LINE Webhook component of Sipeed PicoClaw. The vulnerability is located in the `webhook.ParseRequest` function within `pkg/channels/line/line.go`. While the system correctly validates the HMAC signature of incoming LINE webhooks, it fails to implement replay suppression or idempotency checks using the stable `message.id` provided by the platform. A remote, unauthenticated attacker can capture a valid signed webhook and replay it to the `/webhook/line` endpoint, causing the application to republish the event to the internal message bus and execute downstream agent actions multiple times. As of the advisory date, the issue is marked as 'not planned' for fixing by the maintainers.
Affected products
- Sipeed PicoClaw <= 0.2.9
Timeline
- 2026-07-18: disclosed: Vulnerability disclosed via GitHub issue and VulDB
- 2026-07-18: advisory: CVE-2026-16083 published