Vulnerability · Published Jan 13, 2026 · Assigned by TYPO3

CVE-2026-0859TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool

Medium 5.2

In plain English

A medium-severity unsafe deserialization in TYPO3 CMS from TYPO3. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.2Medium

Exploit odds (30 days)0.2%top 92.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

TYPO3's mail‑file 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	typo3/cms-core	14.0.2	GHSA-7vp9-x248-9vr9
Packagist	typo3/cms-core	13.4.23	GHSA-7vp9-x248-9vr9
Packagist	typo3/cms-core	12.4.41	GHSA-7vp9-x248-9vr9
Packagist	typo3/cms-core	11.5.49	GHSA-7vp9-x248-9vr9
Packagist	typo3/cms-core	10.4.55	GHSA-7vp9-x248-9vr9

Affected products (as reported)

Vendor	Product	Versions
TYPO3	TYPO3 CMS	10.0.0 – before 10.4.5511.0.0 – before 11.5.4912.0.0 – before 12.4.4113.0.0 – before 13.4.2314.0.0 – before 14.0.2

Weakness: CWE-502 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H

References

https://typo3.org/security/advisory/typo3-core-sa-2026-004 vendor-advisory
Git commit of main branch patch
Git commit of 13.4 branch patch
Git commit of 12.4 branch patch