Blossom through 1.17.1 Authorization Bypass via Folder Endpoints

Advisories

Blossom through 1.17.1 Authorization Bypass via Folder Endpoints

Severity: medium
Date: 10/30/2026
Affecting: Blossom <= 1.17.1
CVE: CVE-2026-119659
CWE: CWE-639 Authorization Bypass Through User-Controlled Key
CVSS: 5.3
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
References: https://github.com/blossom-editor/blossom/issues/213
https://github.com/blossom-editor/blossom/blob/v1.17.1/blossom-backend/backend/src/main/java/com/blossom/backend/server/folder/FolderService.java#L123-L202
https://github.com/blossom-editor/blossom/blob/v1.17.1/blossom-backend/backend/src/main/resources/mapper/FolderMapper.xml#L64-L92
https://hackmd.io/@hieuPenguinnn/blossom-folder-idor-cross-user-modify-delete
https://github.com/blossom-editor/blossom
Credit: hieuPenguinnn
Description: Blossom through 1.17.1 contains an authorization bypass vulnerability that allows authenticated users to access other users' folders because FolderService queries filter only on folder id. Attackers can supply another user's folder id to /folder/info, /folder/upd, /folder/open or /folder/del to read storage paths, rename, toggle visibility, or delete folders.

Ready to get Started?

Explore VulnCheck, a next-generation Cyber Threat Intelligence platform, which provides exploit and vulnerability intelligence to help you prioritize and remediate vulnerabilities that matter.

Vulnerability Prioritization
Prioritize vulnerabilities that matter based on the threat landscape and defer vulnerabilities that don't.
Early Warning System
Real-time alerting of changes in the vulnerability landscape so that you can take action before the attacks start.

Schedule a Demo