CVE-2026-45068

Updated on 27 May 2026

Severity

Awaiting Analysis

Details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Overview

About vulnerability

Description

Symfony Mailer selects a transport via the MAILER_DSN environment variable / configuration (e.g. smtp://..., sendmail://..., native://default). SendmailTransport invokes the local sendmail binary and supports two modes: -bs (speak SMTP over stdin: the default) and -t (read the message on stdin, pass recipients as command-line arguments).

In -t mode, recipient addresses are appended to the sendmail command line without a -- end-of-options separator. A recipient address beginning with - (which Symfony\Component\Mime\Address accepts as valid) is therefore interpreted by sendmail as a command-line option rather than an address.

Resolution

The SendmailTransport transport now ensure -- is set before the list of recipients.

The patch for this issue is available here for branch 5.4.

Credits

Symfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.

Details

Affected product:
Symfony
Affected packages:
mailer @ v6.4.34 (+7 more)

Fixes