CVE-2026-102471

In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the vertx-mail-client does not sanitize CR (\r) or LF (\n) characters in user-supplied email header names and values before writing them into the SMTP DATA section. A CR/LF sequence embedded in a name or value passed to MailMessage.addHeader(), MailMessage.setHeaders(), MailAttachment.addHeader(), or MailAttachment.setHeaders() is written verbatim to the wire, allowing an attacker to inject arbitrary headers (e.g. Bcc, Reply-To, Content-Type) or prepend body content to the outgoing message. The same weakness affects MIME part metadata set via MailAttachment.setContentType(), setDisposition(), setDescription(), and setContentId(), which are written directly into MIME part headers without validation. A secondary weakness in Utils.mustEncode(char) additionally allows a bare LF in a From display-name to bypass Q-encoding and reach the wire unchanged. An unauthenticated attacker who can control any header name, header value, or attachment metadata field passed to the mail client (for example via a web form or API that feeds into MailMessage) can exploit this to redirect email copies, spoof headers, or tamper with message structure. The impacted component is io.vertx:vertx-mail-client.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:eclipse:vert.x:*:*:*:*:*:*:*:*
cpe:2.3:a:eclipse:vert.x:*:*:*:*:*:*:*:*
cpe:2.3:a:eclipse:vert.x:5.2.0:*:*:*:*:*:*:*

History

20 Oct 2026, 19:32

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.9
CPE cpe:2.3:a:eclipse:vert.x:*:*:*:*:*:*:*:*
cpe:2.3:a:eclipse:vert.x:5.2.0:*:*:*:*:*:*:*
References () https://github.com/vert-x3/vertx-mail-client/security/advisories/GHSA-rm5c-2c7f-gc5g - () https://github.com/vert-x3/vertx-mail-client/security/advisories/GHSA-rm5c-2c7f-gc5g - Vendor Advisory
References () https://gitlab.eclipse.org/security/cve-assignment/-/work_items/348 - () https://gitlab.eclipse.org/security/cve-assignment/-/work_items/348 - Issue Tracking, Third Party Advisory
First Time Eclipse
Eclipse vert.x

14 Oct 2026, 20:17

Type Values Removed Values Added
CWE CWE-93

14 Oct 2026, 19:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-10-14 19:17

Updated : 2026-10-20 19:32


NVD link : CVE-2026-102471

Mitre link : CVE-2026-102471

CVE.ORG link : CVE-2026-102471


JSON object : View

Products Affected

eclipse

  • vert.x
CWE
CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')