Stored XSS via unescaped AJAX response text
Published Jul 17, 2026 · Updated Jul 17, 2026
Stored XSS in Symfony UX Autocomplete 2.2.0 through 2.35.x and 3.0.0 allows remote attackers to execute script in users’ browsers. The _createAutocompleteWithRemoteData() method inserts each AJAX text value into an HTML template literal without escaping, causing the browser to parse attacker-controlled markup as executable content. Exploitation requires user-supplied dropdown data and a user to open an autocomplete widget backed by that data; execution is confined to that site’s browser context.
Summary
What happened
Stored XSS in Symfony UX Autocomplete 2.2.0 through 2.35.x and 3.0.0 allows remote attackers to execute script in users’ browsers. The _createAutocompleteWithRemoteData() method inserts each AJAX text value into an HTML template literal without escaping, causing the browser to parse attacker-controlled markup as executable content. Exploitation requires user-supplied dropdown data and a user to open an autocomplete widget backed by that data; execution is confined to that site’s browser context.
The record
- CVE
- CVE-2026-49216
- Published
- Jul 17, 2026
- Updated
- Jul 17, 2026
- Vendor
- Symfony
- Product
- Symfony UX
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 17, 2026CVE publishedPublication date reported by the CVE source.
- Jul 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.36.0
- Affected versionversion=>= 3.0.0, < 3.1.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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