Bookstack
CVE-2020-11055
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 5.4 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, user interaction required. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAI
In BookStack greater than or equal to 0.18.0 and less than 0.29.2, there is an XSS vulnerability in comment creation. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in composer
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. In BookStack greater than or equal to 0.18.0 and less than 0.29.2, there is an XSS vulnerability in comment creation. A user with permission to create comments could POST HTML directly to the system to be saved in a comment, which would then be executed/displayed to others users viewing the comment. Through this vulnerability custom JavaScript code could be injected and therefore ran on other user machines. This most impacts scenarios where not-trusted users are given permission to create comments. This has been fixed in 0.29.2. Affected products include: Bookstackapp Bookstack.
Know when Bookstack gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
In BookStack greater than or equal to 0.18.0 and less than 0.29.2, there is an XSS vulnerability in comment creation. A user with permission to create comments could POST HTML directly to the system to be saved in a comment, which would then be executed/displayed to others users viewing the comment. Through this vulnerability custom JavaScript code could be injected and therefore ran on other user machines. This most impacts scenarios where not-trusted users are given permission to create comments. This has been fixed in 0.29.2.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)NVD
bookstack is vulnerable to Improper Access Control. Rated critical severity (CVSS 9.8), this vulnerability is remotely e
In BookStack before version 0.30.4, a user with permissions to edit a page could add an attached link which would execut
bookstack is vulnerable to Cross-Site Request Forgery (CSRF). Rated medium severity (CVSS 6.8), this vulnerability is re
Book Stack version 23.10.2 allows filtering local files on the server. Rated medium severity (CVSS 6.5), this vulnerabil
bookstack is vulnerable to Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). Rated medium
bookstack is vulnerable to Unrestricted Upload of File with Dangerous Type. Rated medium severity (CVSS 6.5), this vulne
bookstack is vulnerable to Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). Rated medium
bookstack is vulnerable to Server-Side Request Forgery (SSRF). Rated medium severity (CVSS 6.5), this vulnerability is r
bookstack is vulnerable to Unrestricted Upload of File with Dangerous Type. Rated medium severity (CVSS 5.7), this vulne
BookStack chapter export functionality allows unauthenticated remote attackers to bypass access controls via manipulatio
Cross-site Scripting (XSS) - Stored in GitHub repository bookstackapp/bookstack prior to v22.02.3. Rated medium severity
bookstack is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). Rated m
Exploit-DB