What’s Vulnerable › Vulnerabilities

CVE-2026-49216: Symfony UX: XSS in symfony/ux-autocomplete via unescaped AJAX response data

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-17 · updated 2026-10-24
• Weakness: CWE-79

Description

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.

Affected products

• symfony ux: from 2.2.0 before 2.36.0; 3.0.0 — fixed in 2.36.0

How to fix

Upgrade to a fixed version: symfony ux 2.36.0. Check the vendor advisory for mitigations.

References

• https://github.com/symfony/ux/commit/842ae54bc74de389299f975f01aafae272cb0019
• https://github.com/symfony/ux/releases/tag/v2.36.0
• https://github.com/symfony/ux/releases/tag/v3.1.0
• https://github.com/symfony/ux/security/advisories/GHSA-mwqm-4fw3-cjvr

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