CVE-2021-41113: TYPO3 is an open source PHP based web content management system released under the GNU GPL.

TYPO3 is an open source PHP based web content management system released under the GNU GPL.

TYPO3 is an open source PHP based web content management system released under the GNU GPL. It has been discovered that the new TYPO3 v11 feature that allows users to create and share deep links in the backend user interface is vulnerable to cross-site-request-forgery. The impact is the same as described in TYPO3-CORE-SA-2020-006 (CVE-2020-11069). However, it is not limited to the same site context and does not require the attacker to be authenticated. In a worst case scenario, the attacker could create a new admin user account to compromise the system. To successfully carry out an attack, an attacker must trick his victim to access a compromised system. The victim must have an active session in the TYPO3 backend at that time. The following Same-Site cookie settings in $GLOBALS[TYPO3_CONF_VARS][BE][cookieSameSite] are required for an attack to be successful: SameSite=strict: malicious evil.example.org invoking TYPO3 application at good.example.org and SameSite=lax or none: malicious evil.com invoking TYPO3 application at example.org. Update your instance to TYPO3 version 11.5.0 which addresses the problem described.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses typo3, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.64%, higher than 50% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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