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CVE-2026-49740
Unsafe Deserialization in typo3/cms-core (CVE-2026-49740)
Summary
vulnerability in typo3/cms-core (CVE-2026-49740). Risk of unauthorized operations or information disclosure. Exploitable via ``VariableFrontend``. Mitigation: upgrade to `14.3.3` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-49740** has been found in typo3/cms-core.
Attackers can target a specific entry point like ``VariableFrontend`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade typo3/cms-core to **14.3.3** or later.
If unsure, ask your IT team or search "typo3/cms-core CVE-2026-49740" on the vendor's site.
CVE-2026-49740 (typo3/cms-core) — CWE-502 /
Attack surface: `VariableFrontend` / `Registry`
Patched: `14.3.3` — 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
**unsafe deserialization** (CWE-502) exists in typo3/cms-core. Attackers reach the vulnerable code path via ``VariableFrontend`` without authentication.
📍 Affected scope
typo3/cms-core — . Attack surface: `VariableFrontend` / `Registry`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **14.3.3**.
🛡️ 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/cms-core' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'typo3/cms-core' . | 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/cms-core` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade typo3/cms-core to 14.3.3ステージング環境で 14.3.3 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
composer
typo3/cms-core
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"14.3.3"}]}]
Packagist
typo3/cms-core
[{"type":"ECOSYSTEM","events":[{"introduced":"14.0.0"},{"fixed":"14.3.3"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-49740
- package https://github.com/TYPO3/typo3
- web https://github.com/TYPO3/typo3/commit/48bcf24f31f52cc0b43d3bea4984634bd2cf85c7
- web https://github.com/TYPO3/typo3/commit/87cd7c5b710c44d3606fed277b040a75dc6a9c02
- web https://typo3.org/security/advisory/typo3-core-sa-2026-018
- web https://github.com/TYPO3/typo3/security/advisories/GHSA-c78m-c52x-jgwp
- web https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2026-49740.yaml
- web https://github.com/advisories/GHSA-c78m-c52x-jgwp