TYPO3 CMS mailfile spool deserialization PHP RCE (v10-14)
CVE-2026-0859 Published on January 13, 2026
TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool
TYPO3's mailfile spool deserialization flaw lets local users with write access to the spool directory craft a malicious file that is deserialized during the mailer:spool:send command, enabling arbitrary PHP code execution on the web server. This issue affects TYPO3 CMS versions 10.0.0-10.4.54, 11.0.0-11.5.48, 12.0.0-12.4.40, 13.0.0-13.4.22 and 14.0.0-14.0.1.
Weakness Type
What is a Marshaling, Unmarshaling Vulnerability?
The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
CVE-2026-0859 has been classified to as a Marshaling, Unmarshaling vulnerability or weakness.
Products Associated with CVE-2026-0859
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Affected Versions
TYPO3 CMS:- Version 10.0.0 and below 10.4.55 is affected.
- Version 11.0.0 and below 11.5.49 is affected.
- Version 12.0.0 and below 12.4.41 is affected.
- Version 13.0.0 and below 13.4.23 is affected.
- Version 14.0.0 and below 14.0.2 is affected.
Vulnerable Packages
The following package name and versions may be associated with CVE-2026-0859
| Package Manager | Vulnerable Package | Versions | Fixed In |
|---|---|---|---|
| composer | typo3/cms-core | >= 14.0.0, <= 14.0.1 | 14.0.2 |
| composer | typo3/cms-core | >= 13.0.0, <= 13.4.22 | 13.4.23 |
| composer | typo3/cms-core | >= 12.0.0, <= 12.4.40 | 12.4.41 |
| composer | typo3/cms-core | >= 11.0.0, <= 11.5.48 | 11.5.49 |
| composer | typo3/cms-core | >= 10.0.0, <= 10.4.54 | 10.4.55 |
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.