CVE-2025-43855

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.

CVSS v4.0

8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v4.0

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

EPSS

0.40% chance of exploitation in the next 30 days, 33th percentile

Published

2025-04-24

Updated

2025-05-14

Proof-of-concept exploits (1)

• advisories/GHSA-pj3v-9cm8-gvj8

References

• CVE Record
• NVD entry

Related

• CVE-2025-43853
• CVE-2025-43858
• CVE-2025-4380
• CVE-2025-43860
• CVE-2025-43708
• CVE-2025-43862