TI-2026-30655 Aliases CVE-2026-42353 GHSA-jfgf-83c5-2c4m

Path traversal / SSRF in i18next-http-middleware via user-controlled language and namespace parameters

MEDIUM 42CWE-22Published 2026-05-08 · Updated 2026-05-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00387 32nd percentileScored 2026-11-07

Fix Fixed i18next-http-middleware (i18next): 3.9.3i18next-http-middleware (npm): 3.9.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
i18next	i18next-http-middleware	before 3.9.3	3.9.3	Patch available	CNA
—	i18next-http-middleware (npm)	before 3.9.3	3.9.3	Patch available	GHSA-jfgf-83c5-2c4m

i18next-http-middleware Vendori18next Affected before 3.9.3 Fixed in 3.9.3 Patch available CNA
i18next-http-middleware (npm) Vendor— Affected before 3.9.3 Fixed in 3.9.3 Patch available GHSA-jfgf-83c5-2c4m

Remediation

Fix · CNA i18next-http-middleware (i18next) Fixed in 3.9.3
Fix · GHSA-jfgf-83c5-2c4m i18next-http-middleware (npm) Fixed in 3.9.3 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-42353
2026-10-03 Alias added: GHSA-jfgf-83c5-2c4m

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-42353

Other 3

TI-2026-83444 Shared built-in object corruption in i18next resource merging CVSS 3.1MEDIUM 5.9
TI-2026-82145 Query parameter injection in i18next-http-backend via lng or ns CVSS 3.1LOW 3.7
TI-2026-68453 Incomplete URL validation in i18next-http-backend permits SSRF CVSS 3.1LOW 3.7
TI-2026-35995 i18next-http-middleware missingKeyHandler does not reject keys whose segments contain prototype-polluting names CVSS 3.1CRITICAL 9.1
TI-2026-35994 i18next-fs-backend: Prototype pollution via crafted missing-key string CVSS 3.1CRITICAL 9.1
TI-2026-79749 Protocol-relative URL injection in i18next-http-backend CVSS 4.0LOW 2.3

See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences