Vulnerability in locize (CVE-2026-41886)
Summary
Vulnerability in locize (CVE-2026-41886). Data can be tampered with by attackers. Exploitable via locize. Mitigation: upgrade to 4.0.21 or later.
Original description
The description as published by the source.
locize is a localization platform that connects code and i18n setup. Prior to version 4.0.21, the locize client SDK registers a window.addEventListener("message", …) handler that dispatches to registered internal handlers (editKey, commitKey, commitKeys, isLocizeEnabled, requestInitialize, …) without validating event.origin. The pre-patch listener in src/api/postMessage.js gates dispatch on event.data.sender === "i18next-editor-frame" — that value sits inside the attacker-controlled message payload, not the browser-enforced origin. Any web page that could embed or be embedded by a locize-enabled host — an iframe on a third-party page, a window.open-ed victim, a parent frame reaching down — could send a crafted postMessage and trigger the internal handlers. This issue has been patched in version 4.0.21.
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-2026-41886 has been found in locize.
Attackers can target a specific entry point like locize over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: upgrade locize to 4.0.21 or later.
If unsure, ask your IT team or search "locize CVE-2026-41886" on the vendor's site.
CVE-2026-41886 (locize) — CWE-346 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: locize / editKey / commitKey / commitKeys
Patched: 4.0.21 — apply immediately
Workaround: No workaround short of upgrading.
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-346) exists in locize. Attackers reach the vulnerable code path via locize without authentication.
Check the vendor advisory for the affected versions of locize. Attack surface: locize / editKey / commitKey / commitKeys.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to 4.0.21.
Workaround: No workaround short of upgrading.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'locize' . 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
-
1Identify exposure identify
grep -r 'locize' . | 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
locizeを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
No workaround short of upgrading.パッチが適用されるまでの応急処置として、No workaround short of upgrading. を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade locize to 4.0.21ステージング環境で 4.0.21 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。
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4Post-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 developer.mozilla.org
- web github.com