XSS in Bookstackapp Bookstack

CVE-2020-26210

In BookStack before version 0.30.4, a user with permissions to edit a page could add an attached link which would execute untrusted JavaScript code when clicked by a viewer of the page. Dangerous content may remain in the database after this update. If you think this could have been exploited the linked advisory provides a SQL query to test. As a workaround, 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 version 0.30.4.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.012 (63.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-26210?
CVE-2020-26210 is a high-severity vulnerability in Bookstackapp Bookstack, classified under Cross-site Scripting. CVSS score: 7.7/10. Published 2020-11-03.
How severe is CVE-2020-26210?
High severity. CVSS v3 base score is 7.7 out of 10.