Vulnerability · Published Sep 16, 2026 · Assigned by VulnCheck
CVE-2026-92598Nodemailer before 9.1.0 IDN/Punycode Domain Allow-list Bypass
Medium 6.5
In plain English
A medium-severity security flaw in nodemailer from nodemailer. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-nodemailer | no fix listed | DEBIAN-CVE-2026-92598 |
| Debian:13 | node-nodemailer | no fix listed | DEBIAN-CVE-2026-92598 |
| Debian:14 | node-nodemailer | 10.0.0+~8.0.1-1 | DEBIAN-CVE-2026-92598 |
| Ubuntu:22.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-92598 |
| Ubuntu:24.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-92598 |
| Ubuntu:26.04:LTS | node-nodemailer | no fix listed | UBUNTU-CVE-2026-92598 |
| Ubuntu:26.10 | node-nodemailer | no fix listed | UBUNTU-CVE-2026-92598 |
| npm | nodemailer | 9.1.0 | GHSA-wmmp-3585-3rmp |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nodemailer | nodemailer | 0 – before 9.1.0 |
Weakness: CWE-436 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
References
- GitHub Security Advisory (GHSA-wmmp-3585-3rmp) vendor-advisory
- Patch Commit patch
- Patch Commit patch
- VulnCheck Advisory: Nodemailer before 9.1.0 IDN/Punycode Domain Allow-list Bypass third-party-advisory