CVE-2026-50190

high

Description

Shaarli is a personal bookmarking service. Versions prior to 0.16.3 are vulnerable to stored XSS in `application/front/controller/visitor/BookmarkListController.php`. The `permalink` handler concatenates the raw `$bookmark->getTitle()` into the `pagetitle` template variable and the RainTPL template emits it into the document `<title>` element without HTML escaping. A bookmark title containing `</title><script>...</script>` closes the document title early and the injected script executes in the Shaarli origin for any visitor of `/shaare/{hash}`. Shaarli's metadata fetcher copies a remote page's `<title>` text verbatim into the local bookmark title, so an attacker who hosts an attacker-controlled URL and convinces an administrator to bookmark it plants the payload with no further interaction — and the resulting permalink fires for every visitor including the administrator on first save, providing a one-shot administrator account takeover. Version 0.16.3 fixes the issue.

References

https://github.com/shaarli/Shaarli/security/advisories/GHSA-xm98-h5jj-64xv

Details

Source: Mitre, NVD

Published: 2026-08-20

Updated: 2026-08-20

Risk Information

CVSS v2

Base Score: 3.5

Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N

Severity: Low

CVSS v3

Base Score: 4.8

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 8.6

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00101