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Fencer Intel
high 8.6

CVE-2026-50190 json

Shaarli vulnerable to stored XSS via raw bookmark title in document <title> element on public permalink page

published 5mo ago modified 16d ago also EUVD-2026-63551 , GHSA-xm98-h5jj-64xv

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository shaarli/Shaarli. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
8.6
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • shaarli_project shaarli 0.16.3

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/shaarli/Shaarli/security/advisories/GHSA-xm98-h5jj-64xv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.6 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
CNA 4.0 8.6 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • shaarli Shaarli

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of shaarli/Shaarli published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.