What is CVE-2026-3455?

CVE-2026-3455 is a medium-severity vulnerability in Nodemailer Mailparser, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-03.

How severe is CVE-2026-3455?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Nodemailer Mailparser

CVE-2026-3455

Versions of the package mailparser before 3.9.3 are vulnerable to Cross-site Scripting (XSS) via the textToHtml() function due to the improper sanitisation of URLs in the email content. An attacker can execute arbitrary scripts in victim browsers by adding extra quote " to the URL with embedded malicious JavaScript code.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-03-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.5th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Nodemailer Mailparser
Mailparser — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security.snyk.io/vuln/SNYK-JS-MAILPARSER-15204032 (Third Party Advisory)
github.com/nodemailer/mailparser/commit/921a67df4cfb38f0b411037d7b26fbd4d5411b08 (Patch)
gist.github.com/hayageek/7fcb225e3b1ea9a341d560403fbb585a (Exploit, Third Party Advisory)
github.com/nodemailer/mailparser/issues/412 (Issue Tracking)

Frequently asked questions

What is CVE-2026-3455?: CVE-2026-3455 is a medium-severity vulnerability in Nodemailer Mailparser, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-03.
How severe is CVE-2026-3455?: Medium severity. CVSS v3 base score is 6.1 out of 10.