Cross-Site Scripting (XSS) in symfony/ux-autocomplete (CVE-2026-49216)
Summary
Cross-site scripting in symfony/ux-autocomplete (CVE-2026-49216). Risk of unauthorized operations or information disclosure. Exploitable via text. Mitigation: upgrade to 3.1.0 or later.
Original description
The description as published by the source.
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 (${item[labelField]}) 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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-49216 has been found in symfony/ux-autocomplete.
Attackers can target a specific entry point like text over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade symfony/ux-autocomplete to 3.1.0 or later.
If unsure, ask your IT team or search "symfony/ux-autocomplete CVE-2026-49216" on the vendor's site.
CVE-2026-49216 (symfony/ux-autocomplete) — CWE-79 / CVSS v3 5.4
Attack vector: remote (network-reachable)
Attack surface: text / option / item / escape
Patched: 3.1.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in symfony/ux-autocomplete. Attackers reach the vulnerable code path via text.
Check the vendor advisory for the affected versions of symfony/ux-autocomplete. Attack surface: text / option / item / escape.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 3.1.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'symfony/ux-autocomplete' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'symfony/ux-autocomplete' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
symfony/ux-autocompleteを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade symfony/ux-autocomplete to 3.1.0ステージング環境で 3.1.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web github.com