CVE-2026-82854 PUBLISHED

Nodemailer before 8.0.3 SMTP Command Injection via envelope.size

Assigner: VulnCheck
Reserved: 31.08.2026 Published: 31.08.2026 Updated: 31.08.2026

Nodemailer before 8.0.4 is vulnerable to SMTP command injection through the unsanitized envelope.size parameter. When an application passes a custom envelope object with a size property containing CRLF characters to sendMail(), the value is concatenated into the SMTP MAIL FROM command (as SIZE=...) without sanitization, allowing injection of arbitrary SMTP commands such as RCPT TO to silently add attacker-controlled recipients. Exploitation requires the application to expose the envelope size to attacker-controlled input, as Nodemailer does not include size in the default auto-constructed envelope.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 9.3

Product Status

Vendor nodemailer
Product nodemailer
Versions Default: unaffected
  • affected from 0 to 8.0.3 (excl.)
  • Version 8.0.3 is unaffected

Credits

  • esquilichi reporter

References

Problem Types

  • Improper Neutralization of CRLF Sequences ('CRLF Injection') CWE