Description
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.
Published: 2026-08-31
Score: 9.3 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Mon, 31 Aug 2026 09:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Nodemailer before 8.0.3 SMTP Command Injection via envelope.size
First Time appeared Nodemailer
Nodemailer nodemailer
Weaknesses CWE-93
CPEs cpe:2.3:a:nodemailer:nodemailer:*:*:*:*:*:*:*:*
Vendors & Products Nodemailer
Nodemailer nodemailer
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, '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'}


Subscriptions

Nodemailer Nodemailer
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-31T08:46:28.405Z

Reserved: 2026-08-31T08:37:27.053Z

Link: CVE-2026-82854

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-31T09:17:05.463

Modified: 2026-08-31T09:17:05.463

Link: CVE-2026-82854

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-31T10:30:17Z

Weaknesses
  • CWE-93

    Improper Neutralization of CRLF Sequences ('CRLF Injection')