CVE-2026-92598 Nodemailer before 9.1.0 IDN/Punycode Domain Allow-list Bypass
Attackers can bypass domain allow-lists in Nodemailer by exploiting IDN normalization flaws to send emails to unauthorized domains.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-92598?
CVE-2026-92598 is a high-severity vulnerability in nodemailer, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Nodemailer before 9.1.0 fails to apply UTS-46 normalization when encoding international domain names, causing the domain resolver to compute a different Punycode A-label than standards-compliant parsers. Attackers can craft recipient addresses with invisible characters or compatibility mappings that pass domain allow-list checks but are delivered to attacker-controlled domains via SMTP.
Weakness: CWE-436
Which versions are affected by CVE-2026-92598?
2 open source packages ship an affected version, including nodemailer.
| Package | Affected | Fixed in |
|---|---|---|
nodemailer npm | All versions | 9.1.0 |
nodemailer npm | All versions | 9.1.0 |
How do I fix CVE-2026-92598?
Upgrade nodemailer to 9.1.0 or later.
Is CVE-2026-92598 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-92598 exists.
Sources
Also known as CLEANSTART-2026-CB36815, CLEANSTART-2026-EW00525, CLEANSTART-2026-NC98199, DEBIAN-CVE-2026-92598, ECHO-9f3a-0677-e28a, GHSA-r7q5-h7cx-p54x and 18 more.