Incomplete URL validation in i18next-http-backend permits SSRF
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 11 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-918 and the CVSS impact.
Summary
The i18next-http-backend npm package before 4.0.2 has incomplete URL validation in custom loadPath and addPath templates. When a template begins with {{lng}} or {{ns}}, attacker-controlled language or namespace values can turn it into an absolute or protocol-relative URL, so requests can leave the intended origin (CWE-918). An attacker who can supply those values can cause URL injection or server-side request forgery, and the default /locales/{{lng}}/{{ns}}.json template is not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
i18next-http-backend is a backend layer for i18next that loads translation resources in Node.js, browsers, and Deno. Prior to 4.0.2, attacker-controlled language or namespace values interpolated into a custom loadPath or addPath that begins directly with {{lng}} or {{ns}} can make colon-based input become an absolute URL or, in browsers, make a double-slash namespace become a protocol-relative URL. The resulting request can leave the intended origin and cause URL injection or server-side request forgery. The default /locales/{{lng}}/{{ns}}.json template and templates with a leading path or origin are not affected because the placeholder does not occupy the URL's structural beginning. This issue is fixed in version 4.0.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- 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-backend | before 4.0.2 | 4.0.2 | Patch available | CNA |
| — | i18next-http-backend (npm) | before 4.0.2 | 4.0.2 | Patch available | GHSA-xvq9-wjp8-hwqf |
- i18next-http-backend Vendori18next Affected before 4.0.2 Fixed in 4.0.2 Patch available CNA
- i18next-http-backend (npm) Vendor— Affected before 4.0.2 Fixed in 4.0.2 Patch available GHSA-xvq9-wjp8-hwqf
Remediation
Upgrade the npm package i18next-http-backend to version 4.0.2, which fixes the flaw. Red Hat lists these products as affected with no fix available: Migration Toolkit for Applications 8, Multicluster Engine for Kubernetes, Network Observability Operator, OpenShift Service Mesh 3, Red Hat AMQ Broker 7 and other products.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA i18next-http-backend (i18next) Fixed in 4.0.2
- Fix · GHSA-xvq9-wjp8-hwqf i18next-http-backend (npm) Fixed in 4.0.2 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Migration Toolkit for Applications 8 | Affected | No fix yet: Fix deferred |
| Multicluster Engine for Kubernetes | Affected | No fix yet: Fix deferred |
| Network Observability Operator | Affected | No fix yet: Fix deferred |
| OpenShift Service Mesh 3 | Affected | No fix yet: Fix deferred |
| Red Hat AMQ Broker 7 | Affected | No fix yet: Fix deferred |
| Red Hat Advanced Cluster Management for Kubernetes 2 | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Data Grid 8 | Affected | No fix yet: Fix deferred |
| Red Hat Edge Manager 1 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-06 Threatist record created from CVE-2026-105800
- 2026-10-06 Alias added: GHSA-xvq9-wjp8-hwqf
- 2026-10-06 Fix available: npm/[email protected] · GHSA-xvq9-wjp8-hwqf
- 2026-10-06 CVSS score added · GHSA-xvq9-wjp8-hwqf
- 2026-10-06 Weakness changed · GHSA-xvq9-wjp8-hwqf
- 2026-10-06 5 new references · GHSA-xvq9-wjp8-hwqf
- 2026-10-06 CISA SSVC decision points changed
- 2026-10-06 Priority changed: LOW → MEDIUM
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-07 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 4
More i18next vulnerabilities
- 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-2026-35995 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
- TI-2026-30208 i18next-http-backend has Path Traversal & URL Injection via Unsanitised lng/ns CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-105800 · CVE Program
- CVE-2026-105800 · NVD
- FIRST EPSS
- GHSA-xvq9-wjp8-hwqf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-105800 · Red Hat security data · CC BY 4.0
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