XSS in Symfony Ux

CVE-2026-49216

Symfony UX is a JavaScript ecosystem for Symfony. From 2.2.0 until 2.36.0 and 3.1.0, the Stimulus controller in symfony/ux-autocomplete renders AJAX response items in _createAutocompleteWithRemoteData() by interpolating the text field into HTML template literals (<div>${item[labelField]}</div>) rather than text, allowing attacker-controlled markup from user-supplied dropdown values to execute in the browser of any user who opens an autocomplete widget backed by the same data. This issue is fixed in versions 2.36.0 and 3.1.0.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-49216: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

  • Symfony Ux — versions >= 3.0.0, < 3.1.0, < 2.36.0, 3.0.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-49216?
CVE-2026-49216 is a medium-severity vulnerability in Symfony Ux, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-07-17.
How severe is CVE-2026-49216?
Medium severity. CVSS v3 base score is 5.4 out of 10.