# CVE-2026-82854

## Summary

- **CVE ID:** CVE-2026-82854
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (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)
- **CWE:** CWE-93
- **Published:** Aug 31, 2026
- **Last Modified:** 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.

## Affected Products

- nodemailer — nodemailer (0)
- nodemailer — nodemailer (8.0.3)

## References

- [CNA](https://github.com/nodemailer/nodemailer/security/advisories/GHSA-c7w3-x93f-qmm8)
- [CNA](https://www.vulncheck.com/advisories/nodemailer-before-8.0.3-smtp-command-injection-via-envelope-size)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 1.13%
- **EPSS Percentile:** 64.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._