Plunk is an open-source email platform built on top of AWS SES. Prior to 0.8.0, a CRLF header injection vulnerability was discovered in SESService.ts, where user-supplied values for from.name, subject, custom header keys/values, and attachment filenames were interpolated directly into raw MIME messages without sanitization. An authenticated API user could inject arbitrary email headers (e.g. Bcc, Reply-To) by embedding carriage return/line feed characters in these fields, enabling silent email forwarding, reply redirection, or sender spoofing. The fix adds input validation at the schema level to reject any of these fields containing \r or \n characters, consistent with the existing validation already applied to the contentId field. This vulnerability is fixed in 0.8.0.
History

Tue, 07 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
First Time appeared Useplunk
Useplunk plunk
Vendors & Products Useplunk
Useplunk plunk

Mon, 06 Apr 2026 16:45:00 +0000

Type Values Removed Values Added
Description Plunk is an open-source email platform built on top of AWS SES. Prior to 0.8.0, a CRLF header injection vulnerability was discovered in SESService.ts, where user-supplied values for from.name, subject, custom header keys/values, and attachment filenames were interpolated directly into raw MIME messages without sanitization. An authenticated API user could inject arbitrary email headers (e.g. Bcc, Reply-To) by embedding carriage return/line feed characters in these fields, enabling silent email forwarding, reply redirection, or sender spoofing. The fix adds input validation at the schema level to reject any of these fields containing \r or \n characters, consistent with the existing validation already applied to the contentId field. This vulnerability is fixed in 0.8.0.
Title Plunk has a CRLF Email Header Injection in raw MIME message construction allows authenticated API user to inject arbitrary email headers
Weaknesses CWE-93
References
Metrics cvssV3_1

{'score': 8.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-06T16:10:05.699Z

Reserved: 2026-03-31T19:38:31.616Z

Link: CVE-2026-34975

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-06T17:17:11.210

Modified: 2026-04-06T17:17:11.210

Link: CVE-2026-34975

cve-icon Redhat

No data.