---
cve: "CVE-2026-82854"
severity: "CRITICAL"
cvss: 9.3
epss: "1.1%"
vendor: "nodemailer"
kev: false
exploited: false
published: "2026-08-31 09:17:05"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T07:25:33+02:00"
---

# CVE-2026-82854

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

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-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 4e702e97650aaff442a7bc040957ba9c53c614b8 (Commit)

## Referenzen

- <https://github.com/nodemailer/nodemailer/security/advisories/GHSA-c7w3-x93f-qmm8>
- <https://www.vulncheck.com/advisories/nodemailer-before-8.0.3-smtp-command-injection-via-envelope-size>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-82854) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_