Vulnerability in Nodemailer
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.
Vulnerability class: CRLF Injection
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.020 (80.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 80.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.020 · change: +0.008
Affected products
Weakness classification (CWE)
References
- github.com/nodemailer/nodemailer/security/advisories/GHSA-c7w3-x93f-qmm8 (vendor-advisory)
- www.vulncheck.com/advisories/nodemailer-before-8.0.3-smtp-command-injection-via… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-82854?
- CVE-2026-82854 is a critical-severity vulnerability in Nodemailer, classified under CRLF Injection. CVSS score: 9.8/10. Published 2026-08-31.
- How severe is CVE-2026-82854?
- Critical severity. CVSS v3 base score is 9.8 out of 10.