CVE-2020-26260

Name: CVE-2020-26260
Creator: NVD / NIST
Published: 2020-12-09T17:15:30.477+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.4/10EPSS 0.83%

Last modified Jun 17, 2026

CVE-2020-26260 is a medium-severity vulnerability rated 6.4/10 on the CVSS scale. BookStack is a platform for storing and organising information and documentation. In BookStack before version 0.30.5, a user with permissions to edit a page could set certain image URL's to manipulate functionality in the exporting system, which would allow them to make server side requests and/or have access to a wider scope of files within the BookStack file storage locations. EPSS estimates a 0.83% chance of exploitation in the next 30 days.

Description

BookStack is a platform for storing and organising information and documentation. In BookStack before version 0.30.5, a user with permissions to edit a page could set certain image URL's to manipulate functionality in the exporting system, which would allow them to make server side requests and/or have access to a wider scope of files within the BookStack file storage locations. The issue was addressed in BookStack v0.30.5. As a workaround, page edit permissions could be limited to only those that are trusted until you can upgrade.

Metrics

CVSS 3.1

6.4/10

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

EPSS Probability

0.83%

52.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Bookstackapp	Bookstack	< 0.30.5

References

https://bookstackapp.com/blog/beta-release-v0-30-5/Vendor Advisory
https://github.com/BookStackApp/BookStack/releases/tag/v0.30.5Release Notes, Third Party Advisory
https://github.com/BookStackApp/BookStack/security/advisories/GHSA-8wfc-w2r5-x7crThird Party Advisory
https://bookstackapp.com/blog/beta-release-v0-30-5/Vendor Advisory
https://github.com/BookStackApp/BookStack/releases/tag/v0.30.5Release Notes, Third Party Advisory
https://github.com/BookStackApp/BookStack/security/advisories/GHSA-8wfc-w2r5-x7crThird Party Advisory

Timeline

Published: Dec 9, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26260?

How severe is CVE-2020-26260?

CVE-2020-26260 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.83% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26260?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26260?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST