CVE-2026-100701

Nodemailer versions 5.0.0 through 10.0.1 use a process-global DNS cache that is keyed only by the DNS host, while each cache entry also stores the caller-specific TLS servername. When two direct TLS/SMTPS transports (secure: true) resolve the same non-IP host with different tls.servername values, the first transport's servername is returned on the cache hit and overwrites the second transport's explicitly configured value, so Nodemailer sends the wrong SNI value and validates the peer certificate against the wrong identity. In multi-tenant services or SNI-routed SMTP gateways, an attacker who can prime the cache can cause a victim transport to connect to the attacker's TLS virtual host and accept the attacker's certificate even with rejectUnauthorized: true, disclosing the victim's SMTP credentials. Fixed in 10.0.2.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-6vj9-mwq6-2f5v
https://www.vulncheck.com/advisories/nodemailer-5.0.0-through-10.0.1-tls-servername-cache-confusion

Configurations

No configuration.

History

26 Sep 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-26 14:16

Updated : 2026-09-30 16:32

NVD link : CVE-2026-100701

Mitre link : CVE-2026-100701

CVE.ORG link : CVE-2026-100701

JSON object : View

Products Affected

No product.

CWE

CWE-295

Improper Certificate Validation

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