Categories
CVE-2026-47344

Cross-Site Scripting (XSS) in typo3/html-sanitizer (CVE-2026-47344)

Summary

Cross-site scripting in typo3/html-sanitizer (CVE-2026-47344). Risk of unauthorized operations or information disclosure. Exploitable via ALLOW_INSECURE_RAW_TEXT. Mitigation: upgrade to 2.3.2 or later.

Original description

The description as published by the source.

When ALLOW_INSECURE_RAW_TEXT is enabled, whitespace-variant closing tags (e.g., ) are not recognized by the sanitizer but accepted by browsers as valid end tags, allowing subsequent content to escape sanitization. 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-2026-47344 has been found in typo3/html-sanitizer.
Attackers can target a specific entry point like ALLOW_INSECURE_RAW_TEXT over the network to misuse the product.
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-2026-47344" on the vendor's site.

CVE-2026-47344 (typo3/html-sanitizer) — CWE-79
Attack surface: ALLOW_INSECURE_RAW_TEXT
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.

❓ What is the problem

Cross-site scripting (XSS) (CWE-79) exists in typo3/html-sanitizer. Attackers reach the vulnerable code path via ALLOW_INSECURE_RAW_TEXT.

📍 Affected scope

Check the vendor advisory for the affected versions of typo3/html-sanitizer. Attack surface: ALLOW_INSECURE_RAW_TEXT.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 2.3.2.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

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

  1. 1
    Identify 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。

  2. 2
    Apply 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。

  3. 3
    Post-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

composer typo3/html-sanitizer
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.2"}]}]
Packagist typo3/html-sanitizer
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.2"}]}]

References

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