CVE-2026-45068

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

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.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, SendmailTransport in -t mode appended recipient addresses to the sendmail command line without a -- end-of-options separator, allowing an address beginning with - to be interpreted as a sendmail command-line option instead of an address. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.