CVE-2026-100701

MEDIUM CVSS 4.0: 6.0 EPSS 0.11%
Updated Sep 30, 2026
Nodemailer
Parameter Value
CVSS 6.0 (MEDIUM)
Affected Versions 5.0.0 — 10.0.2
Fixed In 10.0.2
Type CWE-295 (Improper Certificate Validation)
Vendor Nodemailer
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v4.0

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Nodemailer Nodemailer
cpe:2.3:a:nodemailer:nodemailer:*:*:*:*:*:*:*:*
5.0.0 10.0.2