CVE-2026-49216: Symfony UX Autocomplete XSS via unescaped AJAX response data

CVE-2026-49216 · Severity: medium · CVSS 4 · Published 2026-07-17

Symfony UX Autocomplete is a tool used by web developers to create smart dropdown menus that suggest results as a user types. A security flaw allows malicious data stored in the database to be executed as code in the web browser of any user who interacts with these dropdowns. This could lead to unauthorized actions being performed on behalf of users or the theft of sensitive session information.

Technologies: symfony/ux-autocomplete (Packagist). Vendors: Packagist, Symfony.

Quick answers

Is CVE-2026-49216 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-49216 being exploited in the wild.
How severe is CVE-2026-49216?
Medium severity, with a CVSS score of 4, published 17 July 2026.
Which products and versions are affected?
symfony/ux-autocomplete (Packagist) ECOSYSTEM:introduced=2.2.0,fixed=2.36.0; Symfony UX Autocomplete >= 2.2.0, < 2.36.0; >= 3.0.0, < 3.1.0.
Is there a fix for CVE-2026-49216?
Yes. symfony/ux-autocomplete (Packagist): upgrade to 2.36.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-49216 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-49216?
Check whether you run symfony/ux-autocomplete (Packagist) or Symfony UX Autocomplete at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • symfony/ux-autocomplete (Packagist): upgrade to 2.36.0 or later
    composer require symfony/ux-autocomplete:^2.36.0

Technical details

A stored Cross-Site Scripting (XSS) vulnerability exists in the Stimulus controller of symfony/ux-autocomplete. The root cause is located in the _createAutocompleteWithRemoteData() function, which interpolates the 'text' field from AJAX responses directly into HTML template literals (e.g., <div>${item[labelField]}</div>) instead of treating it as plain text. An attacker can supply malicious markup via user-controllable fields that are later served by the autocomplete AJAX endpoint. When a victim interacts with the autocomplete widget, the payload executes in their browser. The issue is fixed in versions 2.36.0 and 3.1.0 by implementing default HTML escaping using TomSelect's escape helper.

Affected products

  • symfony ux-autocomplete >= 2.2.0, < 2.36.0
  • symfony ux-autocomplete >= 3.0.0, < 3.1.0

Identifiers

  • CVE-2026-49216
  • GHSA-mwqm-4fw3-cjvr

Timeline

  • 2026-05-24: patched: Fix committed to repository
  • 2026-05-29: advisory: Security releases v2.36.0 and v3.1.0 published
  • 2026-07-17: disclosed: CVE-2026-49216 published to NVD

References

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