SB20260930102 - Inefficient regular expression complexity in nodemailer

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Main Vulnerability Database SB20260930102

SB20260930102 - Inefficient regular expression complexity in nodemailer

Published: September 30, 2026 Updated: September 30, 2026

Security Bulletin ID SB20260930102
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Inefficient regular expression complexity (CVE-ID: CVE-2026-100700)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in the addressparser free-text fallback when parsing crafted address header values. A remote attacker can submit a crafted whitespace-free input string that causes quadratic backtracking to cause a denial of service.

The resulting event-loop blockage can stall the entire Node.js process.


Remediation

Install update from vendor's website.

References