Blossom through 1.17.1 contains an authorization bypass vulnerability that allows authenticated non-readonly users to modify other users' pictures by supplying arbitrary picture ids. Attackers can call the picture delete, /picture/del/batch, or /picture/star endpoints to permanently delete victims' images and stored files or change their star status.
https://hackmd.io/@hieuPenguinnn/blossom-picture-idor-cross-user-delete
https://github.com/blossom-editor/blossom/issues/214
Published: 2026-10-30
Updated: 2026-10-30
Base Score: 5.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:P
Severity: Medium
Base Score: 5.4
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Severity: Medium
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00326