Read the docs
TI-2025-38647 Aliases CVE-2025-62380GHSA-q4w9-x3rv-4c8j

Mailgen has HTML Injection and XSS Filter Bypass in Plaintext Emails

Priority MEDIUM 54CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

mailgen is a Node.js package that generates responsive HTML e-mails for sending transactional mail. Mailgen versions through 2.0.31 contain an HTML injection vulnerability in plaintext emails generated with the generatePlaintext method when user generated content is supplied. The plaintext generation code attempts to strip HTML tags using a regular expression and then decodes HTML entities, but tags that include certain Unicode line separator characters are not matched and removed. These encoded tags are later decoded into valid HTML content, allowing unexpected HTML to remain in output intended to be plaintext. Projects are affected if they call Mailgen.generatePlaintext with untrusted input and then render or otherwise process the returned string in a context where HTML is interpreted. This can lead to execution of attacker supplied script in the victim’s browser. Version 2.0.32 fixes the issue.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00452 39th percentileScored 2026-11-07
Fix Fixed mailgen (eladnava): 2.0.32mailgen (npm): 2.0.32

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
eladnavamailgenbefore 2.0.322.0.32Patch availableCNA
—mailgen (npm)before 2.0.322.0.32Patch availableGHSA-q4w9-x3rv-4c8j
  • mailgen Vendoreladnava Affected before 2.0.32 Fixed in 2.0.32 Patch available CNA
  • mailgen (npm) Vendor— Affected before 2.0.32 Fixed in 2.0.32 Patch available GHSA-q4w9-x3rv-4c8j

Remediation

  • Fix · CNA mailgen (eladnava) Fixed in 2.0.32
  • Fix · GHSA-q4w9-x3rv-4c8j mailgen (npm) Fixed in 2.0.32 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-62380
  2. 2026-10-03 Alias added: GHSA-q4w9-x3rv-4c8j

References

Advisory 1

Other 3

  • TI-2025-38634 Mailgen vulnerable to HTML injection and cross-site scripting via plaintext email generation CVSS 4.0LOW 2.9
  • TI-2025-37057 Mailgen: HTML injection vulnerability in plaintext e-mails CVSS 4.0LOW 2.7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences