Medium severity · published Sep 16, 2026
CVE-2026-92598
Nodemailer before 9.1.0 IDN/Punycode Domain Allow-list Bypass
6.5
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
nodemailer · nodemailer
before 9.1.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-92598
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-92598
github.com
https://github.com/nodemailer/nodemailer/commit/259c32d
github.com
https://github.com/nodemailer/nodemailer/commit/b212ac4
github.com
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-wmmp-3585-3rmp
www.vulncheck.com
https://www.vulncheck.com/advisories/nodemailer-before-9.1.0-idn-punycode-domain-allow-list-bypass
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