Headline
GHSA-7vp9-x248-9vr9: TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool
Problem
Local platform users who can write to TYPO3’s mail‑file spool directory can craft a file that the system will automatically deserialize without any class restrictions. This flaw allows an attacker to inject and execute arbitrary PHP code in the public scope of the web server.
The vulnerability is triggered when TYPO3 is configured with $GLOBALS['TYPO3_CONF_VARS']['MAIL']['transport_spool_type'] = 'file'; and a scheduler task or cron job runs the command mailer:spool:send. The spool‑send operation performs the insecure deserialization that is at the core of this issue.
Solution
Update to TYPO3 versions 10.4.55 ELTS, 11.5.49 ELTS, 12.4.41 LTS, 13.4.23 LTS, 14.0.2 that fix the problem described.
Credits
Thanks to Vitaly Simonovich for reporting this issue, and to TYPO3 security team members Elias Häußler and Oliver Hader for fixing it.
References
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2026-0859
TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool
Moderate severity GitHub Reviewed Published Jan 13, 2026 in TYPO3/typo3 • Updated Jan 13, 2026
Package
composer typo3/cms-core (Composer)
Affected versions
>= 14.0.0, <= 14.0.1
>= 13.0.0, <= 13.4.22
>= 12.0.0, <= 12.4.40
>= 11.0.0, <= 11.5.48
>= 10.0.0, <= 10.4.54
Patched versions
14.0.2
13.4.23
12.4.41
11.5.49
10.4.55
Problem
Local platform users who can write to TYPO3’s mail‑file spool directory can craft a file that the system will automatically deserialize without any class restrictions. This flaw allows an attacker to inject and execute arbitrary PHP code in the public scope of the web server.
The vulnerability is triggered when TYPO3 is configured with $GLOBALS[‘TYPO3_CONF_VARS’][‘MAIL’][‘transport_spool_type’] = 'file’; and a scheduler task or cron job runs the command mailer:spool:send. The spool‑send operation performs the insecure deserialization that is at the core of this issue.
Solution
Update to TYPO3 versions 10.4.55 ELTS, 11.5.49 ELTS, 12.4.41 LTS, 13.4.23 LTS, 14.0.2 that fix the problem described.
Credits
Thanks to Vitaly Simonovich for reporting this issue, and to TYPO3 security team members Elias Häußler and Oliver Hader for fixing it.
References
- TYPO3-CORE-SA-2026-004
References
- GHSA-7vp9-x248-9vr9
- https://nvd.nist.gov/vuln/detail/CVE-2026-0859
- TYPO3/typo3@3225d70
- TYPO3/typo3@722bf71
- TYPO3/typo3@e0f0cee
- https://typo3.org/security/advisory/typo3-core-sa-2026-004
Published to the GitHub Advisory Database
Jan 13, 2026
Last updated
Jan 13, 2026