PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-49740 TYPO3 CVE debrief

CVE-2026-49740 is a PHP Object Injection vulnerability in TYPO3's cache frontend (VariableFrontend) and persistent key-value store (Registry). The vulnerability allows an attacker with write access to the underlying storage backend (cache store or sys_registry database table) to inject a crafted serialized payload, potentially triggering PHP Object Injection. This could be exploited to achieve Remote Code Execution or other high-impact effects. However, 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, 11.0.0-11.5.51, 12.0.0-12.4.46, 13.0.0-13.4.31, and 14.0.0-14.3.3.

Vendor
TYPO3
Product
TYPO3 CMS
CVSS
MEDIUM 6.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-07-15
Advisory published
2026-06-09
Advisory updated
2026-07-15

Who should care

Users of TYPO3 CMS versions before 10.4.57, 11.0.0-11.5.51, 12.0.0-12.4.46, 13.0.0-13.4.31, and 14.0.0-14.3.3 should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by the deserialization of PHP payloads without integrity validation or class restrictions in TYPO3's cache frontend and persistent key-value store. An attacker with write access to the underlying storage backend could inject a crafted serialized payload to trigger PHP Object Injection.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to a patched version of TYPO3 CMS (10.4.57, 11.5.51, 12.4.46, 13.4.31, or 14.3.3 or later)
  • Restrict write access to the underlying storage backend (cache store or sys_registry database table)
  • Monitor the storage backend for suspicious activity

Evidence notes

The CVE-2026-49740 vulnerability was published on [cve-org](https://www.cve.org/CVERecord?id=CVE-2026-49740) and details can be found on [nvd](https://nvd.nist.gov/vuln/detail/CVE-2026-49740). Additional information is available at [ref-4](https://github.com/TYPO3/typo3/commit/48bcf24f31f52cc0b43d3bea4984634bd2cf85c7), [ref-5](https://github.com/TYPO3/typo3/commit/87cd7c5b710c44d3606fed277b040a75dc6a9c02), and [ref-6](https://typo3.org/security/advisory/typo3-core-sa-2026-018).

Sources and references

Verified primary and authoritative sources

  • CVE-2026-49740 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-49740

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-49740 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-49740

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://github.com/TYPO3/typo3/commit/48bcf24f31f52cc0b43d3bea4984634bd2cf85c7

    f4fb688c-4412-4426-b4b8-421ecf27b14a

  • Source reference

    Unverified legacy reference

    URL: https://github.com/TYPO3/typo3/commit/87cd7c5b710c44d3606fed277b040a75dc6a9c02

    f4fb688c-4412-4426-b4b8-421ecf27b14a

  • Source reference

    Unverified legacy reference

    URL: https://typo3.org/security/advisory/typo3-core-sa-2026-018

    f4fb688c-4412-4426-b4b8-421ecf27b14a

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.