Description

tRPC allows users to build & consume fully typesafe APIs without schemas or code generation. In versions starting from 11.0.0 to before 11.1.1, an unhandled error is thrown when validating invalid connectionParams which crashes a tRPC WebSocket server. This allows any unauthenticated user to crash a tRPC 11 WebSocket server. Any tRPC 11 server with WebSocket enabled with a createContext method set is vulnerable. This issue has been patched in version 11.1.1.

Classification

CVE ID: CVE-2025-43855

CVSS Base Severity: HIGH

CVSS Base Score: 8.7

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected Products

Vendor: trpc

Product: trpc

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.1% (probability of being exploited)

EPSS Percentile: 28.5% (scored less or equal to compared to others)

EPSS Date: 2025-05-23 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: true

References

https://nvd.nist.gov/vuln/detail/CVE-2025-43855
https://github.com/trpc/trpc/security/advisories/GHSA-pj3v-9cm8-gvj8
https://github.com/trpc/trpc/commit/9beb26c636d44852e0f407f3d7a82ad54df65b4d

Timeline