CVE-2026-92598 (CVSS 6.5)

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.

Is your site exposed to CVE-2026-92598?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Weakness Type (CWE)

CWE-436 CWE-436

References

Other References

https://github.com/nodemailer/nodemailer/commit/259c32d https://github.com/nodemailer/nodemailer/commit/b212ac4 https://github.com/nodemailer/nodemailer/security/advisories/GHSA-wmmp-3585-3rmp https://www.vulncheck.com/advisories/nodemailer-before-9.1.0-idn-punycode-domain-allow-list-bypass

Frequently Asked Questions

What is CVE-2026-92598? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-92598? +

CVE-2026-92598 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2026-92598? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-42272

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall handles URL-encoded …

CVE-2025-54368

uv is a Python package and project manager written in Rust. In versions 0.8.5 and earlier, remote ZIP archives were …

CVE-2026-42274

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs rule …

CVE-2026-42273

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs host …

CVE-2026-47344

When ALLOW_INSECURE_RAW_TEXT is enabled, whitespace-variant closing tags (e.g., </style\t>) are not recognized by the sanitizer but accepted by browsers as …

CVE-2026-44974

@hapi/content provided HTTP Content-* headers parsing. Prior to 6.0.2, Content.disposition() retained the last occurrence of each duplicate parameter while Content.type() …

CVE-2026-92598