p PatchFirst

CVE-2026-41886

CVE-2026-41886 · locize Client SDK: Cross-origin DOM XSS & Handler Hijack Through Missing e.origin Validation in InContext Editor

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 0.1% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • locize

    Versions
    • < 4.0.21: Affected

    No fix published

  • locize npm

    Affected ranges
    • SEMVER: < 4.0.21

    Update to 4.0.21

Original sources

Check your server →