Vulnerability in apostrophe (CVE-2026-53609)
Summary
Vulnerability in apostrophe (CVE-2026-53609). Confidential information can be exposed externally. Exploitable via __proto__. Mitigation: upgrade to 4.31.0 or later.
Original description
The description as published by the source.
ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, apos.util.set() traverses dot-notation paths without sanitizing __proto__, allowing an authenticated editor to write arbitrary values to Object.prototype via the $pullAll patch operator. A confirmed gadget in publicApiCheck() causes this to bypass authorization on all piece-type REST API endpoints for every subsequent unauthenticated request, for the lifetime of the Node.js process. As of time of publication, no known patched versions are available.
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-2026-53609 has been found in apostrophe.
Attackers can target a specific entry point like __proto__ over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade apostrophe to 4.31.0 or later.
If unsure, ask your IT team or search "apostrophe CVE-2026-53609" on the vendor's site.
CVE-2026-53609 (apostrophe) — CWE-1321 / CVSS v3 9.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: __proto__ / Object.prototype / constructor / prototype
Patched: 4.31.0 — 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.
A vulnerability (CWE-1321) exists in apostrophe. Attackers reach the vulnerable code path via __proto__.
Check the vendor advisory for the affected versions of apostrophe. Attack surface: __proto__ / Object.prototype / constructor / prototype.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 4.31.0.
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 'apostrophe' . 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 'apostrophe' . | 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
apostrophe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 apostrophe to 4.31.0ステージング環境で 4.31.0 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 nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com
- web github.com