Vulnerability in Pebcak Go-Mail
CVE-2025-59937
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
EPSS: 0.005 (40.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Pebcak Go-mail
- Wneessen Go-mail — versions < 0.7.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Exploit, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-59937?
- CVE-2025-59937 is a critical-severity vulnerability in Pebcak Go-Mail, classified under Argument Injection. CVSS score: 9.1/10. Published 2025-09-29.
- How severe is CVE-2025-59937?
- Critical severity. CVSS v3 base score is 9.1 out of 10.