BookStack < 26.05.4 Broken Access Control via Image Gallery API
BookStack before 26.05.4 contains a broken access control vulnerability that allows authenticated API users with image-update or image-delete permissions to manipulate other users' avatars by exploiting missing content-type restrictions in the Image Gallery API endpoints. Attackers can supply a user avatar's ID to the API controller, which loads any image type without the web controller's gallery and drawio restrictions, and when the avatar's uploaded_to field matches a page ID accessible to the attacker, the authorization check passes allowing the attacker to rename, replace, or delete the target user's avatar without requiring user-management permission.
CVE-2026-67204
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-67204
BookStack
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/BookStackApp/BookStack",
"vendor": "BookStackApp",
"product": "BookStack",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "26.05.4",
"versionType": "custom"
}
],
"packageURL": "pkg:github/BookStackApp/BookStack",
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-67204
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #5452 · Revision 1
- Added to Heist Feed
- Publisher date