CVE-2026-118258 is a low-severity (CVSS 3.7) CWE-74 vulnerability. No vendor fix is recorded yet; mitigation options are listed below.
i18next-http-backend is a backend layer for i18next that loads translation resources in Node.js, browsers, and Deno. Prior to 4.0.4, interpolateUrl inserts unencoded language and namespace…
Description
i18next-http-backend is a backend layer for i18next that loads translation resources in Node.js, browsers, and Deno. Prior to 4.0.4, interpolateUrl inserts unencoded language and namespace values into loadPath or addPath templates without rejecting ampersand (&), equals (=), or semicolon (;) query separators. When a template places lng or ns in the query string and an attacker controls that value, the attacker can add or override parameters on browser or server-side translation requests, potentially exposing other namespaces or tenants or changing backend behavior through the application's network position and credentials. This vulnerability is the result of an incomplete fix for CVE-2026-41691. This issue is fixed in version 4.0.4.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-118258 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-118258 in your dependencies?
Find it across , including transitive dependencies.