CVE-2026-0859
TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool
Impact
### 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](https://typo3.org/security/advisory/typo3-core-sa-2026-004)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | typo3/cms-core | >= 14.0.0, <= 14.0.1 | 14.0.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Typo3 | Typo3 | from 10.0.0 before 10.4.55 from 11.0.0 before 11.5.49 from 12.0.0 before 12.4.41 from 13.0.0 before 13.4.23 from 14.0.0 before 14.0.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/TYPO3/typo3/commit/3225d705080a1bde57a66689621c947da5a4782f
- https://github.com/TYPO3/typo3/commit/722bf71c118b0a8e4f2c2494854437d846799a13
- https://github.com/TYPO3/typo3/commit/e0f0ceee480c203fbb60b87454f5f193e541d27f
- https://typo3.org/security/advisory/typo3-core-sa-2026-004
- https://github.com/advisories/GHSA-7vp9-x248-9vr9
- https://github.com/TYPO3/typo3/security/advisories/GHSA-7vp9-x248-9vr9
- https://nvd.nist.gov/vuln/detail/CVE-2026-0859