Inefficient Algorithmic Complexity in nodemailer - #VU153022
Published: September 30, 2026
Vulnerability identifier: #VU153022
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in the SMTP client response parser when processing multiline SMTP server replies. A remote attacker can stream continuation lines without a completion line to cause a denial of service.
The issue is reachable during SMTP greeting and EHLO reply processing before client authentication.
Affected software
nodemailer
Remediation
Install security update from vendor's website.
nodemailer - update to 10.0.10