CVE-2025-43855
tRPC allows users to build & consume fully typesafe APIs without schemas or code generation.
Overview
CVE-2025-43855 is a known-severity vulnerability. It was published on April 24, 2025.
Technical 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.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2025-43855?
CVE-2025-43855 is a known-severity vulnerability. It was published on April 24, 2025.
How severe is CVE-2025-43855?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2025-43855?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-43855?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-43855 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.