--- title: "TYPO3-CORE-SA-2018-008: Cross-Site Scripting in Frontend User Login" url: "https://news.typo3.com/security/advisory/typo3-core-sa-2018-008" description: It has been discovered, that TYPO3 CMS is vulnerable to cross-site scripting. image: "https://news.typo3.com/_assets/d1e01514e4c4a5b3147940fa2ec50682/Images/og-image-news.jpg" date: 2026-06-11 modified: 2026-06-11 categories: - "Developer & Technology" - TYPO3 CMS --- # TYPO3-CORE-SA-2018-008: Cross-Site Scripting in Frontend User Login - [Developer & Technology](https://news.typo3.com/article/category/developer-technology) - Security / [TYPO3 CMS](https://news.typo3.com/article/category/security/typo3-cms) TYPO3-CORE-SA-2018-008: Cross-Site Scripting in Frontend User Login =================================================================== 11 December 2018 ![A laptop screen displaying a list of security advisories](https://news.typo3.com/typo3temp/assets/_processed_/d/c/csm_security_blog_default_77f8e86036.webp) It has been discovered, that TYPO3 CMS is vulnerable to cross-site scripting. - ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/b8266fdc667b773926c59081862ab148.jpeg)[Oliver Hader](https://news.typo3.com/article/author/oliver-hader) - **Component Type:** TYPO3 CMS - **Vulnerable subcomponent:** Frontend user login - **Release Date:** December 11, 2018 - **Vulnerability Type:** Cross-Site Scripting - **Affected Versions:** 7.0.0-7.6.31, 8.0.0-8.7.20 and 9.0.0-9.5.1 - **Severity:** Medium - **Suggested CVSS v3.0:** [AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C) - **CVE:** not assigned yet ### Problem Description Failing to properly encode user input, login status display is vulnerable to cross-site scripting in the website frontend. A valid user account is needed in order to exploit this vulnerability - either a backend user or a frontend user having the possibility to modify their user profile. Template patterns that are affected are - *\###FEUSER\_\[fieldName\]###* using system extension *felogin* - ** for regular frontend rendering (pattern can be defined individually using TypoScript setting *config.USERNAME\_substToken*) ### Solution Update to TYPO3 versions 7.6.32, 8.7.21 or 9.5.2 that fix the problem described. **Strong security defaults - Possible customization** Template patterns rendered with system extension *felogin* can be configured using TypoScript. In order to apply strong security defaults property *htmlSpecialChars* is enabled per default. Customizing the rendering process is possible by adjust according TypoScript settings in *plugin.tx\_felogin\_pi1.userfields.fieldName.htmlSpecialChars* ### Credits Thanks to Thomas Löffler who reported this issue and to TYPO3 core team member Benni Mack who fixed the issue. ### General Advice Follow the recommendations that are given in the [TYPO3 Security Guide](https://docs.typo3.org/typo3cms/CoreApiReference/Security/Index.html#security). Please subscribe to the [typo3-announce](http://lists.typo3.org/cgi-bin/mailman/listinfo/typo3-announce) mailing list. ### General Note All security related code changes are tagged so that you can easily look them up in our [review system](https://review.typo3.org/#/q/status:merged+project:Packages/TYPO3.CMS+topic:security,n,z). ![](https://news.typo3.com/typo3temp/assets/t3g/blog/gravatar/cc7cba9757f98fbe05023a139119df74.jpeg) About the Author [Oliver Hader](https://news.typo3.com/article/author/oliver-hader) Core Developer at TYPO3 GmbH,Hof, Germany [Website](https://typo3.com)[Twitter](https://twitter.com/ohader)[LinkedIn](https://www.linkedin.com/in/oliverhader/)[Xing](https://www.xing.com/profile/Oliver_Hader) Oliver started to work with TYPO3 in 2005 and was fascinated by the product and its universe. Since 2007 he is member of the TYPO3 Core Team. After going back to university in 2014 for achieving a postgraduate master degree in internet web science, he is now researching on advanced web technology topics in general and for TYPO3 in particular. In his spare time, Oliver loves to go cycling cross-country in the uplands around Hof (Germany) in northern Bavaria - at the region where he's living as well. [More posts by this author](https://news.typo3.com/article/author/oliver-hader)