CVE-2026-49740 TYPO3 CMS - Insecure Deserialization in Core API
An attacker with local write access to storage can inject serialized payloads to achieve remote code execution via PHP object injection.
- 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-2026-49740?
CVE-2026-49740 is a medium-severity unsafe deserialization vulnerability in TYPO3 CMS, published on 9 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
TYPO3's cache frontend (VariableFrontend) and persistent key-value store (Registry) deserialized PHP payloads without integrity validation or class restrictions. An attacker with write access to the underlying storage backend (cache store or sys_registry database table) could inject a crafted serialized payload to trigger PHP Object Injection, potentially exploiting a gadget chain to achieve Remote Code Execution or other high-impact effects. Exploiting this vulnerability requires direct local write access to the storage, such as the SQL database or file system. This issue affects TYPO3 CMS versions before 10.4.57, 11.0.0-11.5.50, 12.0.0-12.4.45, 13.0.0-13.4.30 and 14.0.0-14.3.2.
Weakness: CWE-502
Which versions are affected by CVE-2026-49740?
10 open source packages ship an affected version, including typo3/cms-core.
| Package | Affected | Fixed in |
|---|---|---|
typo3/cms-core Packagist | All versions | 10.4.57 |
typo3/cms-core Packagist | All versions | 10.4.57 |
typo3/cms-core Packagist | From 11.0.0 | 11.5.51 |
typo3/cms-core Packagist | From 11.0.0 | 11.5.51 |
typo3/cms-core Packagist | From 12.0.0 | 12.4.46 |
typo3/cms-core Packagist | From 12.0.0 | 12.4.46 |
4 more packages
typo3/cms-core Packagist | From 13.0.0 | 13.4.31 |
typo3/cms-core Packagist | From 13.0.0 | 13.4.31 |
typo3/cms-core Packagist | From 14.0.0 | 14.3.3 |
typo3/cms-core Packagist | From 14.0.0 | 14.3.3 |
How do I fix CVE-2026-49740?
Upgrade typo3/cms-core to a fixed version for your release line: 10.4.57, 11.5.51, 12.4.46 or 13.4.31.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-49740 being exploited?
There is no known exploitation of CVE-2026-49740 in the wild and no public exploit code.
Sources
Also known as GHSA-c78m-c52x-jgwp.