Nodemailer before 8.0.4 is vulnerable to SMTP command injection through the unsanitized envelope.size parameter. (CVE-2026-82854)
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.
Nodemailer before 8.0.4 is vulnerable to SMTP command injection through the unsanitized envelope.size parameter. (CVE-2026-82854)
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.
CVSS v3.1
Score 9.8critical
Weaknesses
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-2x76-7hhq-pgvw
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-82854"]
- Ecosystems
- []
- Database Specific Severity
- CRITICAL
- Cvss Version
- 3.1
Threat ID: 6a95a0f1acd9273b4947e23b
Added to database: 08/31/2026, 15:42:41 UTC
Last updated: 08/31/2026, 22:52:14 UTC
Views: 4
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