SB2026040860 - CRLF injection in nodemailer
Published: April 8, 2026
Security Bulletin ID
SB2026040860
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) CRLF injection (CVE-ID: N/A)
The vulnerability allows a remote user to inject arbitrary SMTP commands.
The vulnerability exists due to improper neutralization of CRLF sequences in lib/smtp-connection/index.js when processing a custom envelope.size value in sendMail(). A remote user can supply a crafted envelope.size value containing CRLF characters to inject arbitrary SMTP commands.
This issue can silently add attacker-controlled recipients to outgoing emails. Exploitation requires the application to explicitly pass a custom envelope object with a size property to sendMail().
Remediation
Install update from vendor's website.