Is CVE-2025-43855 actively exploited?

No active exploitation of CVE-2025-43855 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2025-43855 be exploited remotely?

Yes. CVE-2025-43855 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2025-43855?

CVE-2025-43855 has a CVSS score of 8.7 (HIGH).

HOME VULNERABILITIESCVE-2025-43855

HIGH

CVE-2025-43855

CWE-248Published: April 24, 2025· Updated: Jun 17, 2026

8.7

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2025-43855 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeX

Impact

Confidentiality

Integrity

Availability

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/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