← Vulnerability feed

Vulnerability record · CVE-2020-5256 · published 9 March 2020

CVE-2020-5256: Bookstackapp bookstack unrestricted file upload vulnerability

Bookstackapp · Bookstack

BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. The issue was addressed in a series of patches in versions 0.25.3, 0.25.4 and 0.25.5. Users should upgrade to at least v0.25.5 to avoid this vulnerability.

8.8 CVSS 3.1 High EPSS 2.0% · top 20.4% CWE-95 · CWE-95CWE-434 · Unrestricted file upload
8.8CVSS 3.1 base score, v2 9.0
2.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
8References
17 Jun 2026Last modified by NVD

Description

BookStack before version 0.25.5 has a vulnerability where a user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. The issue was addressed in a series of patches in versions 0.25.3, 0.25.4 and 0.25.5. Users should upgrade to at least v0.25.5 to avoid this vulnerability.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3 Release Notes
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.4 Release Notes
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.5 Release Notes
https://github.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx Third Party Advisory
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.3 Release Notes
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.4 Release Notes
https://github.com/BookStackApp/BookStack/releases/tag/v0.25.5 Release Notes
https://github.com/BookStackApp/BookStack/security/advisories/GHSA-g9rq-x4fj-f5hx Third Party Advisory

Track CVE-2020-5256 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-4119Bookstackapp bookstack improper access control vulnerabilitybookstack is vulnerable to Improper Access ControlEPSS 27%8.7CVE-2020-26211Bookstackapp bookstack cross-site scripting vulnerabilityIn 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 …EPSS 1.1%8.7CVE-2020-26210Bookstackapp bookstack cross-site scripting vulnerabilityIn 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 w…EPSS 1.2%6.8CVE-2021-3944Bookstackapp bookstack cross-site request forgery vulnerabilitybookstack is vulnerable to Cross-Site Request Forgery (CSRF)EPSS 0.64%6.5CVE-2023-6199Bookstackapp bookstack server-side request forgery (ssrf) vulnerabilityBook Stack version 23.10.2 allows filtering local files on the server. This is possible because the application is vulnerable to SSRF.EPSS 1.4%6.5CVE-2021-4194Bookstackapp bookstack improper access control vulnerabilitybookstack is vulnerable to Improper Access ControlEPSS 0.71%6.5CVE-2021-3916Bookstackapp bookstack path traversal vulnerabilitybookstack is vulnerable to Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')EPSS 1.2%6.5CVE-2021-3906Bookstackapp bookstack unrestricted file upload vulnerabilitybookstack is vulnerable to Unrestricted Upload of File with Dangerous TypeEPSS 0.67%

Source: NIST National Vulnerability Database (record CVE-2020-5256), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.