{"id":"BIT-mybb-2020-15139","details":"In MyBB before version 1.8.24, the custom MyCode (BBCode) for the visual editor doesn't escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. The weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. After upgrading MyBB to 1.8.24, make sure to update the version attribute in the `codebuttons` template for non-default themes to serve the latest version of the patched `jscripts/bbcodes_sceditor.js` file.","modified":"2026-03-13T04:42:12.766893998Z","published":"2024-03-06T11:00:33.408Z","withdrawn":"2026-03-13T04:28:49.204327Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*"]},"references":[{"type":"WEB","url":"https://github.com/mybb/mybb/commit/37ad29dcd25489a37bdd89ebac761f22492558b0"},{"type":"WEB","url":"https://github.com/mybb/mybb/security/advisories/GHSA-37h7-vfv6-f8rj"},{"type":"WEB","url":"https://mybb.com/versions/1.8.24/"}],"affected":[{"package":{"name":"mybb","ecosystem":"Bitnami","purl":"pkg:bitnami/mybb"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.8.24"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/mybb/BIT-mybb-2020-15139.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}],"schema_version":"1.7.3"}