dbcve.org
Path TraversalWeakness · CWE-22

CVE-2026-42353

HIGH · 8.2 CVSS v3.1 Published 2026-05-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno. Prior to version 3.9.3, i18next-http-middleware passes the user-controlled lng and ns values from getResourcesHandler directly into i18next.services.backendConnector.load(languages, namespaces, …) without any sanitization. Depending on which backend is configured, the unvalidated path segments enable either path traversal or SSRF. This issue has been patched in version 3.9.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The i18next-http-middleware library versions prior to 3.9.3 fail to sanitize user-controlled 'lng' (language) and 'ns' (namespace) parameters from the getResourcesHandler before passing them to i18next.services.backendConnector.load(). This allows attackers to inject path traversal sequences or craft malicious requests leading to SSRF depending on the configured backend storage system.

MitigationUpgrade i18next-http-middleware to version 3.9.3 or later. If upgrading is not immediately possible, implement input validation on the 'lng' and 'ns' parameters before they reach the handler, restricting them to expected patterns only.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate i18next-http-middleware installation
    Check package.json or run 'npm list i18next-http-middleware' or 'yarn list i18next-http-middleware' to find the package and its installed path
    Affected if The package is not found in dependencies at all (not vulnerable, not used)
  2. Determine installed version
    Run 'npm list i18next-http-middleware' to see the exact version number installed, or check the version field in package.json
    Affected if Version is lower than 3.9.3 (e.g., 3.9.2, 3.9.1, 3.x.y where x < 9, or any 2.x version)
  3. Identify if getResourcesHandler is used
    Search source code for usage of getResourcesHandler from i18next-http-middleware, or check if the application exposes endpoints that process lng and ns query parameters from HTTP requests
    Affected if The handler is in use and processes lng/ns parameters from incoming requests (vulnerable code path is active)
  4. Review backend storage configuration
    Examine the i18next configuration to identify which backend is configured (file system, custom HTTP backend, database, etc.) by checking i18next.init() options or i18next configuration files
    Affected if A backend is configured that could allow path traversal (e.g., file system backend) or make outbound HTTP requests (custom HTTP backend), as these are the vectors for the SSRF/path traversal attack

You are affected if i18next-http-middleware version is below 3.9.3 AND your application exposes getResourcesHandler to process lng/ns parameters from user requests, especially with a backend vulnerable to path traversal or SSRF.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade i18next-http-middleware to version 3.9.3 or later. If upgrading is not immediately possible, implement input validation on the 'lng' and 'ns' parameters before they reach the handler, restricting them to expected patterns only.

Recommended fix Moderate confidence

3.9.3

  1. Identify the current version of i18next-http-middleware in your project by checking package.json or package-lock.json
  2. Run npm install [email protected] or npm update i18next-http-middleware to upgrade to the fixed version
  3. Verify the new version is installed correctly by running npm list i18next-http-middleware
  4. Test your application to ensure the lng and ns parameters are now properly sanitized and the path traversal vulnerability is mitigated
  5. Consider reviewing any custom backend implementations to ensure they also handle user input safely

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,370
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42353 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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