CVE-2026-54649

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.

• https://github.com/PunchIn-App/punchin-email/commit/593685ffc0b8eb3949a4838e7bfe1e97b953d084
• https://github.com/PunchIn-App/punchin-email/pull/66
• https://github.com/PunchIn-App/punchin-email/releases/tag/v1.5.0
• https://github.com/PunchIn-App/punchin-email/security/advisories/GHSA-2ph7-69xm-hmwv