Deserialization of Untrusted Data in TYPO3 - CVE-2026-0859
Published: January 14, 2026
Vulnerability identifier: #VU121461
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:U/U:Clear
CVE-ID: CVE-2026-0859
CWE-ID: CWE-502
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: TYPO3
Affected software:
TYPO3
TYPO3
Detailed vulnerability description
The vulnerability allows a local user to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data within Mailer File Spool during the mailer:spool:send command. A local user can pass specially crafted data to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
How to mitigate CVE-2026-0859
Install updates from vendor's website.