CVE-2026-0895 Insecure Deserialization in extension "Mailqueue" (mailqueue)
Attackers can execute arbitrary code via insecure deserialization in the Mailqueue extension, which overrides core security fixes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-0895?
CVE-2026-0895 is a medium-severity unsafe deserialization vulnerability in TYPO3 Extension "Mailqueue", published on 20 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The extension extends TYPO3’ FileSpool component, which was vulnerable to Insecure Deserialization prior to TYPO3-CORE-SA-2026-004 https://typo3.org/security/advisory/typo3-core-sa-2026-004 . Since the related fix is overwritten by the extension, using the extension with a patched TYPO3 core version still allows for Insecure Deserialization, because the affected vulnerable code was extracted from TYPO3 core to the extension. More information about this vulnerability can be found in the related TYPO3 Core Security Advisory TYPO3-CORE-SA-2026-004 https://typo3.org/security/advisory/typo3-core-sa-2026-004 .
Weakness: CWE-502
Which versions are affected by CVE-2026-0895?
4 open source packages ship an affected version, including cpsit/typo3-mailqueue.
| Package | Affected | Fixed in |
|---|---|---|
cpsit/typo3-mailqueue Packagist | All versions | 0.4.3 |
cpsit/typo3-mailqueue Packagist | All versions | 0.4.3 |
cpsit/typo3-mailqueue Packagist | From 0.5.0 | 0.5.1 |
cpsit/typo3-mailqueue Packagist | From 0.5.0 | 0.5.1 |
How do I fix CVE-2026-0895?
Upgrade cpsit/typo3-mailqueue to a fixed version for your release line: 0.4.3 or 0.5.1.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-0895 being exploited?
There is no known exploitation of CVE-2026-0895 in the wild and no public exploit code.
Sources
Also known as GHSA-ggff-9mj3-7246.