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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.7 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- EPSS
- 1.17% probability · 67th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- bookstackapp/bookstack
- Source
- security-advisories@github.com
EPSS 1.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bookstackapp.com/blog/beta-release-v0-30-4/Exploit, Patch, Vendor Advisory
- https://github.com/BookStackApp/BookStack/commit/349162ea139556b2d25e09e155cec84e21cc9227Patch, Third Party Advisory
- https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4Third Party Advisory
- https://github.com/BookStackApp/BookStack/security/advisories/GHSA-7p2j-4h6p-cq3hExploit, Third Party Advisory
- https://bookstackapp.com/blog/beta-release-v0-30-4/Exploit, Patch, Vendor Advisory
- https://github.com/BookStackApp/BookStack/commit/349162ea139556b2d25e09e155cec84e21cc9227Patch, Third Party Advisory
- https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4Third Party Advisory
- https://github.com/BookStackApp/BookStack/security/advisories/GHSA-7p2j-4h6p-cq3hExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.