Cross-Site Scripting (XSS) in typo3/html-sanitizer (CVE-2026-47345)
Summary
Cross-site scripting in typo3/html-sanitizer (CVE-2026-47345). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.3.2 or later.
Original description
The description as published by the source.
Namespace attributes are not encoded correctly during HTML serialization. This allows bypassing the cross-site scripting prevention mechanism of typo3/html-sanitizer before version 2.3.2.
Source: NIST National Vulnerability Database 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-2026-47345 has been found in typo3/html-sanitizer.
Risk of unauthorized operations or information disclosure.
What to do: upgrade typo3/html-sanitizer to 2.3.2 or later.
If unsure, ask your IT team or search "typo3/html-sanitizer CVE-2026-47345" on the vendor's site.
CVE-2026-47345 (typo3/html-sanitizer) — CWE-79
Patched: 2.3.2 — 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 typo3/html-sanitizer.
Check the vendor advisory for the affected versions of typo3/html-sanitizer.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 2.3.2.
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 'typo3/html-sanitizer' . 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 'typo3/html-sanitizer' . | 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
typo3/html-sanitizer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 typo3/html-sanitizer to 2.3.2ステージング環境で 2.3.2 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 typo3.org
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web packagist.org