What is CVE-2026-82661?

CVE-2026-82661 is a medium-severity vulnerability in Nodemailer, classified under CRLF Injection. CVSS score: 5.4/10. Published 2026-08-31.

How severe is CVE-2026-82661?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Nodemailer

CVE-2026-82661

Nodemailer before 8.0.9 fails to sanitize carriage return and line feed characters in list comment fields, allowing attackers to inject arbitrary message headers. An attacker with control over list.*.comment parameters can inject CRLF sequences to create additional headers in generated RFC822 messages, altering mail client behavior and message semantics.

Vulnerability class: CRLF Injection

EPSS: 0.002 (8.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Nodemailer

Weakness classification (CWE)

CWE-93 — CRLF Injection

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-82661?: CVE-2026-82661 is a medium-severity vulnerability in Nodemailer, classified under CRLF Injection. CVSS score: 5.4/10. Published 2026-08-31.
How severe is CVE-2026-82661?: Medium severity. CVSS v3 base score is 5.4 out of 10.