Shaarli through 0.16.9 SSRF via Thumbnail Retrieval update-thumbnail Route

Advisories

Shaarli through 0.16.9 SSRF via Thumbnail Retrieval update-thumbnail Route

severity: medium
date: 10/13/2026
Affecting: Shaarli <= 0.16.9
CVE: CVE-2026-110225
CWE: CWE-918 Server-Side Request Forgery (SSRF)
CVSS: 5.1
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
References: https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/shaarli-open-mode-thumbnail-fetch-ssrf
https://github.com/shaarli/Shaarli/blob/bfeadb4e5856702c05279bb2a5c405f2ed802015/application/front/controller/admin/ThumbnailsController.php#L46-L64
https://github.com/shaarli/Shaarli/blob/bfeadb4e5856702c05279bb2a5c405f2ed802015/application/Thumbnailer.php#L82-L98
https://github.com/shaarli/Shaarli
Credit: hieuPenguinnn
Description: Shaarli through 0.16.9 contains a server-side request forgery vulnerability that allows authenticated users to make the server request internal addresses by fetching bookmark thumbnails without private-address checks. Attackers can create bookmarks pointing to loopback, private, or cloud metadata addresses and trigger ThumbnailsController::ajaxUpdate or saving to send blind GET requests, with open_shaarli exposing this to any visitor.

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