Nodemailer before 8.0.8 disables TLS certificate verification in lib/fetch/index.js through rejectUnauthorized: false, allowing attackers to intercept OAuth2 token requests. Attackers in a machine-in-the-middle position can capture OAuth client secrets, refresh tokens, and access tokens transmitted over compromised HTTPS connections.
https://www.vulncheck.com/advisories/nodemailer-before-8.0.8-tls-certificate-validation-bypass
https://github.com/nodemailer/nodemailer/security/advisories/GHSA-r7g4-qg5f-qqm2
Published: 2026-08-31
Updated: 2026-09-01
Base Score: 6.1
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:P/A:N
Severity: Medium
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Severity: Medium
Base Score: 8.3
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00124