# CVE-2026-82854: node-nodemailer: Nodemailer before 8.0.4 is vulnerable to SMTP command injection through the unsanitized envelope.size parameter

CVE-2026-82854 is fixed in node-nodemailer on 1 platform by DEBIAN-CVE-2026-82854 (version 8.0.4+~7.0.11-1), released September 1, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-82854
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0198
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 31, 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-nodemailer Debian 14 | 8.0.4+~7.0.11-1 | [DEBIAN-CVE-2026-82854](https://patchblox.com/security/data/fix/linux/debian-cve-2026-82854.md) | Sep 1, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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