CVE-2020-26211

Cross-Site Scripting in BookStack

HIGH
8.7
CVSS Score
Published: November 3, 2020 at 09:00 PM UTC
Updated: June 17, 2026 at 03:07 AM UTC
1 product affected across 1 vendorBookStack

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Severity
HIGH8.7
Exploit prediction
EPSS 1%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.30.4
Affected range stops below 0.30.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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