Cloudanix VulnDB

CVE-2026-45067

Medium · 6.5

Symfony has Email Header / SMTP Command Injection via CRLF in Symfony\Component\Mime\Address

CVSS

6.5

EPSS

0.6%

Published

May 27, 2026

CISA due date

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The record

`Symfony\Component\Mime\Address` is the value-object every Symfony Mailer address (to/cc/bcc/from/reply-to) flows through; its constructor is documented as validating the address and throwing on invalid input, so developers treat it as a security boundary. The constructor accepts email addresses whose local-part (the part before `@`) is an RFC-5322 *quoted string* containing raw `\r\n` bytes, e.g. `"x\r\nBcc: attacker@evil"@example.com`. The stored address is later emitted verbatim into (1) the rendered message headers and (2) `SmtpTransport`'s `MAIL FROM:<...>` / `RCPT TO:<...>` protocol lines, turning the embedded CRLF into a new mail header and/or a new SMTP command.

Affected packages

Ecosystem Package Introduced Fixed

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