`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.
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| symfony | symfony | affected |
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No data available yet.
No remediation available yet.
Tracking
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| Source | ID | Title |
|---|---|---|
 Debian DSA |
DSA-6312-1 | symfony security update |
| Debian DSA |
DSA-6317-1 | symfony security update |
 Github GHSA |
GHSA-qpmx-3rfj-7rhv | Symfony has Email Header / SMTP Command Injection via CRLF in Symfony\Component\Mime\Address |
Tue, 14 Jul 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Tue, 14 Jul 2026 18:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | ### 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. | |
| Title | Symfony: Email Header / SMTP Command Injection via CRLF in Symfony\Component\Mime\Address | |
| Weaknesses | CWE-93 | |
| References |
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| Metrics |
cvssV4_0
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Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-14T18:15:43.658Z
Reserved: 2026-05-08T18:45:10.096Z
Link: CVE-2026-45067
Vulnrichment
Updated: 2026-07-14T18:15:40.426Z
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
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CWE-93
Improper Neutralization of CRLF Sequences ('CRLF Injection')