CVE-2026-67204
MEDIUM
5,3
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
MEDIUM
5,4
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: low
Description
AI Translation Available
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.
863
Incorrect Authorization
IncompleteCommon Consequences
Security Scopes Affected:
Confidentiality
Integrity
Access Control
Availability
Potential Impacts:
Read Application Data
Read Files Or Directories
Modify Application Data
Modify Files Or Directories
Gain Privileges Or Assume Identity
Bypass Protection Mechanism
Execute Unauthorized Code Or Commands
Dos: Crash, Exit, Or Restart
Dos: Resource Consumption (Cpu)
Dos: Resource Consumption (Memory)
Dos: Resource Consumption (Other)
Applicable Platforms
Technologies:
Web Server, Database Server, Not Technology-Specific
https://codeberg.org/bookstack/bookstack/releases/tag/v26.05.4
https://github.com/BookStackApp/BookStack/releases/tag/v26.05.4
https://www.bookstackapp.com/blog/bookstack-release-v26-05-4/
https://www.vulncheck.com/advisories/bookstack-broken-access-control-via-image-…