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Advisory details: gitlab / packagist/typo3/cms-core/CVE-2026-0859
Advisory ID gitlab/packagist/typo3/cms-core/CVE-2026-0859
Aliases CVE-2026-0859
GHSA-7vp9-x248-9vr9
Summary 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 * [TYPO3-CORE-SA-2026-004](https://typo3.org/security/advisory/typo3-core-sa-2026-004)
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/packagist/typo3/cms-core/CVE-2026-0859.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-01-13T14:11:54Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/0xxx/CVE-2026-0859.json

Source Advisory: vulnrichment/CVE-2026-0859

View SSVC decision tree
[{'Exploitation': 'none'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]