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High

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

  • Disclosed: 27.05.2026
  • Updated: 11.10.2026 10:22

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 for branch 5.4.

Credits

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

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package symfony/mime < 5.4.52, >= 6.0.0, < 6.4.40, >= 7.0.0, < 7.4.12, >= 8.0.0, < 8.0.12 5.4.52, 6.4.40, 7.4.12, 8.0.12
Composer package symfony/symfony < 5.4.52, >= 6.0.0, < 6.4.40, >= 7.0.0, < 7.4.12, >= 8.0.0, < 8.0.12 5.4.52, 6.4.40, 7.4.12, 8.0.12

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-93
Platform
Composer
Package
symfony/mime, symfony/symfony
Disclosed
27.05.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-qpmx-3rfj-7rhv - CC BY 4.0

Vulnerability history: symfony/symfony

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (100) in the archive
Total entries
100
First → latest
11.2019 06.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 8
  • High 28
  • Medium 51
  • Low 13

Disclosures per year

Severity:
  1. Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes
    High CVE-2026-48489 < 5.4.53, >= 6.0.0, < 6.4.41, >= 7.0.0, < 7.4.13, >= 8.0.0, < 8.0.13 5.4.53, 6.4.41, 7.4.13, 8.0.13
  2. Symfony has Unauthenticated PHP Object Deserialization in MonologBridge server:log Listener
    High CVE-2026-45077 < 5.4.52, >= 6.0.0, < 6.4.40, >= 7.0.0, < 7.4.12, >= 8.0.0, < 8.0.12 5.4.52, 6.4.40, 7.4.12, 8.0.12
  3. Symfony's HEAD Request Bypasses methods: ['GET'] Filter in #[IsGranted] / #[IsSignatureValid] / #[IsCsrfTokenValid]
    High CVE-2026-45075 >= 7.4.0, < 7.4.12, >= 8.0.0, < 8.0.12 7.4.12, 8.0.12
  4. Symfony has Email Header / SMTP Command Injection via CRLF in Symfony\Component\Mime\Address this entry
    High CVE-2026-45067 < 5.4.52, >= 6.0.0, < 6.4.40, >= 7.0.0, < 7.4.12, >= 8.0.0, < 8.0.12 5.4.52, 6.4.40, 7.4.12, 8.0.12
  5. Symfony Vulnerable to Identity Spoofing via Unanchored DN Regex in X509Authenticator
    High CVE-2026-45063 < 5.4.52, >= 6.0.0-BETA1, < 6.4.40, >= 7.0.0-BETA1, < 7.4.12, >= 8.0.0-BETA1, < 8.0.12 5.4.52, 6.4.40, 7.4.12, 8.0.12
  6. Symfony's incorrect parsing of PATH_INFO can lead to limited authorization bypass
    High · 7.3 CVE-2025-64500 >= 2.0.0, < 5.4.50, >= 6.0.0, < 6.4.29, >= 7.0.0, < 7.3.7 5.4.50, 6.4.29, 7.3.7
  7. Symfony vulnerable to command execution hijack on Windows with Process class
    High · 8.4 CVE-2024-51736 < 5.4.46, >= 6.0.0, < 6.4.14, >= 7.0.0, < 7.1.7 5.4.46, 6.4.14, 7.1.7
  8. Symfony Cross-Site Request Forgery vulnerability in the Web Profiler
    High · 8.1 CVE-2014-6072 >= 2.0.0, < 2.3.19, >= 2.4.0, < 2.4.9, >= 2.5.0, < 2.5.4 2.3.19, 2.4.9, 2.5.4
  9. Symfony XML Entity Expansion security vulnerability
    High · 7.5 ghsa-q2gc-gg3x-7942 >= 2.0.0, < 2.0.17 2.0.17
  10. Symfony XML decoding attack vector through external entities
    Critical · 9.8 ghsa-mmcv-fvq8-r9x3 >= 2.0.0, < 2.0.11 2.0.11
  11. Symfony allows direct access of ESI URLs behind a trusted proxy
    High · 7.5 CVE-2014-5245 >= 2.0.0, < 2.3.19, >= 2.4.0, < 2.4.9, >= 2.5.0, < 2.5.4 2.3.19, 2.4.9, 2.5.4
  12. Symfony vulnerable to denial of service via a malicious HTTP Host header
    High · 7.5 CVE-2014-5244 >= 2.0.0, < 2.3.19, >= 2.4.0, < 2.4.9, >= 2.5.0, < 2.5.4 2.3.19, 2.4.9, 2.5.4
  13. Code injection in the way Symfony implements translation caching in FrameworkBundle
    High · 7.5 CVE-2014-4931 >= 2.0.0, < 2.3.19, >= 2.4.0, < 2.4.9, >= 2.5.0, < 2.5.4 2.3.19, 2.4.9, 2.5.4
  14. Symfony Incorrect Access Control
    Critical · 9.8 CVE-2017-11365 >= 2.7.30, < 2.7.32, >= 2.8.23, < 2.8.25, >= 3.2.10, < 3.2.12, >= 3.3.3, < 3.3.5 2.7.32, 2.8.25, 3.2.12, 3.3.5
  15. Symphony Denial of Service Via Overlong Usernames
    High · 7.5 CVE-2016-4423 >= 2.3.0, < 2.3.41, >= 2.4.0, < 2.7.13, >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.3.41, 2.7.13, 2.8.6, 3.0.6
  16. Symfony Cryptographic Vulnerability
    High · 7.5 CVE-2016-1902 >= 2.3.0, < 2.3.37, >= 2.4.0, < 2.6.13, >= 2.7.0, < 2.7.9 2.3.37, 2.6.13, 2.7.9
  17. Symfony Vulnerable to Timing Attack
    High CVE-2015-8125 >= 2.3.0, < 2.3.35, >= 2.7.0, < 2.7.7, >= 2.4.0, < 2.6.12 2.3.35, 2.7.7, 2.6.12
  18. Symphony Vulnerable to PHP Code Injection via YAML Parsing
    High CVE-2013-1348 >= 2.0.0, < 2.0.22 2.0.22
  19. Symfony Arbitrary PHP code Execution
    High CVE-2013-1397 >= 2.2.0-BETA1, < 2.2.0-BETA2, >= 2.0.0, < 2.0.22, >= 2.1.0, < 2.1.7 2.2.0-BETA2, 2.0.22, 2.1.7
  20. Symfony Authentication Bypass
    Critical · 9.8 CVE-2018-11407 >= 2.8.0, < 2.8.37, >= 3.0.0, < 3.3.17, >= 3.4.0, < 3.4.7, >= 4.0.0, < 4.0.7 2.8.37, 3.3.17, 3.4.7, 4.0.7
Show more (16) Showing 20 of 36

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