CVE-2026-54649: Punchin-App Punchin-Email

Low severity, CVSS 2.1. EPSS: 0.8% chance of exploitation in the next 30 days.

punchin-email is a Cloudflare Email Worker that provides two-way role aliases while relaying mail to a private inbox. Prior to 1.5.0, handleInbound delivers inbound alias mail with message.forward(), which silently drops the added Reply-To header intended to route responses through the relay. When a correspondent sends mail to an alias and the operator replies, the mail client can send directly to the correspondent from the private FORWARD_TO inbox address, exposing that address. The disclosure is limited to the operator's own email address and does not expose third-party data or provide code execution or authentication bypass. This issue is fixed in version 1.5.0.

Affected products

• Punchin-App Punchin-Email: before 1.5.0 (fixed in 1.5.0)

Published 2026-09-17. Last modified 2026-09-30.