{"id":"CVE-2021-35210","aliases":["GHSA-h58v-c6rf-g9f7"],"url":"https://o3.security/vulnerability/CVE-2021-35210","summary":"Cross site scripting in the system log","details":"### Impact\n\nIt is possible to inject code into the `tl_log` table that will be executed in the browser when the system log is called in the back end.\n\n### Patches\n\nUpdate to Contao 4.9.16 or 4.11.5.\n\n### Workarounds\n\nDisable the system log module in the back end for all users (especially admin users).\n\n### References\n\nhttps://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021\n\n### For more information\n\nIf you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose).","published":"2021-06-23T11:15:08.170Z","modified":"2026-08-07T17:02:18.620573Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"contao/core-bundle","fixedVersion":"4.9.16"},{"ecosystem":"Packagist","name":"contao/core-bundle","fixedVersion":"4.11.5"},{"ecosystem":"Packagist","name":"contao/contao","fixedVersion":"4.9.16"},{"ecosystem":"Packagist","name":"contao/contao","fixedVersion":"4.11.5"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021.html"},{"type":"ADVISORY","url":"https://github.com/contao/contao/security/advisories/GHSA-h58v-c6rf-g9f7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-35210"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/contao/CVE-2021-35210.yaml"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/contao/core-bundle/CVE-2021-35210.yaml"},{"type":"PACKAGE","url":"https://github.com/contao/contao"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T17:02:18.620573Z"}}