CVE-2025-59937 HIGH

CVE-2025-59937: go-mail has insufficient address encoding when passing mail addresses to the SMTP client

Vendor Wneessen
Product go-mail
Weakness CWE-88
Published September 29, 2025
Last update September 30, 2025

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

go-mail is a comprehensive library for sending mails with Go. In versions 0.7.0 and below, due to incorrect handling of the mail.Address values when a sender- or recipient address is passed to the corresponding MAIL FROM or RCPT TO commands of the SMTP client, there is a possibility of wrong address routing or even ESMTP parameter smuggling. For successful exploitation, it is required that the user's code allows for arbitrary mail address input (i. e. through a web form or similar). If only static mail addresses are used (i. e. in a config file) and the mail addresses in use do not consist of quoted local parts, this should not affect users. This issue is fixed in version 0.7.1

Key dates

02Disclosure timeline

September 29, 2025 CVE published
September 30, 2025 Record updated