CVE-2026-82854

Severity CVSS v4.0:

CRITICAL

Type:

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Publication date:

31/08/2026

Last modified:

31/08/2026

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.

Impact

Vector 4.0

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 v4.0 Severity and Metrics:

Base Score: 9.30 CRITICAL
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

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

9.30

Severity 4.0

CRITICAL

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.80 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

9.80

Severity 3.x

CRITICAL

CVE-2026-82854

Description

Impact

References to Advisories, Solutions, and Tools