BookStackApp BookStack up to 26.05.3 Image Gallery API access control

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability was found in BookStackApp BookStack up to 26.05.3 and classified as problematic. The impacted element is an unknown function of the component Image Gallery API. Executing a manipulation can lead to access control. This vulnerability is registered as CVE-2026-67204. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in BookStackApp BookStack up to 26.05.3. It has been declared as problematic. This vulnerability affects an unknown code of the component Image Gallery API. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at bookstackapp.com. This vulnerability was named CVE-2026-67204 since 07/28/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1068.

Upgrading to version 26.05.4 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.4
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: BookStack 26.05.4

Timelineinfo

07/28/2026 CVE reserved
08/24/2026 +27 days Advisory disclosed
08/24/2026 +0 days VulDB entry created
08/24/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: bookstackapp.com
Status: Confirmed

CVE: CVE-2026-67204 (🔒)
GCVE (CVE): GCVE-0-2026-67204
GCVE (VulDB): GCVE-100-394720

Entryinfo

Created: 08/24/2026 18:04
Changes: 08/24/2026 18:04 (75)
Complete: 🔍
Cache ID: 216::103

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