CVE-2020-26211

In BookStack before version 0.30.4, a user with permissions to edit a page could insert JavaScript code through the use of `javascript:` URIs within a link or form which would run, within the context of the current page, when clicked or submitted. Additionally, a user with permissions to edit a page could insert a particular meta tag which could be used to silently redirect users to a alternative location upon visit of a page. Dangerous content may remain in the database but will be removed before being displayed on a page. If you think this could have been exploited the linked advisory provides a SQL query to test. As a workaround without upgrading, page edit permissions could be limited to only those that are trusted until you can upgrade although this will not address existing exploitation of this vulnerability. The issue is fixed in BookStack version 0.30.4.

• CWE-79

• https://github.com/BookStackApp/BookStack/commit/bbd1384acbe7e52c21f89af69f2dc391c95dbf54Patch, Third Party Advisory
• https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4Release Notes, Third Party Advisory
• https://github.com/BookStackApp/BookStack/security/advisories/GHSA-r2cf-8778-3jgpThird Party Advisory
• https://www.bookstackapp.com/blog/beta-release-v0-30-4/Patch, Vendor Advisory
• https://github.com/BookStackApp/BookStack/commit/bbd1384acbe7e52c21f89af69f2dc391c95dbf54Patch, Third Party Advisory
• https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4Release Notes, Third Party Advisory
• https://github.com/BookStackApp/BookStack/security/advisories/GHSA-r2cf-8778-3jgpThird Party Advisory
• https://www.bookstackapp.com/blog/beta-release-v0-30-4/Patch, Vendor Advisory

Published

Nov 3, 2020

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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