CVE-2026-45067

### Description `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. ### Resolution The `Address` constructor now rejects addresses containing line breaks. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/dc2dbd29211eb4ddc451373fa1374fb926e94604) for branch 5.4. ### Credits We would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
CVSS

No CVSS.

Configurations

No configuration.

History

14 Jul 2026, 18:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-07-14 18:17

Updated : 2026-07-14 20:25


NVD link : CVE-2026-45067

Mitre link : CVE-2026-45067

CVE.ORG link : CVE-2026-45067


JSON object : View

Products Affected

No product.

CWE
CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')