Improper Certificate Validation in nodemailer - #VU132359
Published: May 27, 2026
Vulnerability identifier: #VU132359
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: nodemailer
Affected software:
nodemailer
nodemailer
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive OAuth credentials.
The vulnerability exists due to improper certificate validation in the internal HTTPS fetch client in lib/fetch/index.js when retrieving OAuth2 tokens over HTTPS. A remote attacker can perform a machine-in-the-middle attack using an invalid or self-signed certificate to disclose sensitive OAuth credentials.
The issue affects OAuth2 token requests and related outbound HTTPS requests that use the internal fetch implementation.
Remediation
Install security update from vendor's website.