CVE-2025-54590
webfinger.js is a TypeScript-based WebFinger client that runs in both browsers and Node.js environments.
Overview
CVE-2025-54590 is a known-severity vulnerability. It was published on August 1, 2025.
Technical description
webfinger.js is a TypeScript-based WebFinger client that runs in both browsers and Node.js environments. In versions 2.8.0 and below, the lookup function accepts user addresses for account checking. However, the ActivityPub specification requires preventing access to localhost services in production. This library does not prevent localhost access, only checking for hosts that start with "localhost" and end with a port. Users can exploit this by creating servers that send GET requests with controlled host, path, and port parameters to query services on the instance's host or local network, enabling blind SSRF attacks. This is fixed in version 2.8.1.
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-2025-54590?
CVE-2025-54590 is a known-severity vulnerability. It was published on August 1, 2025.
How severe is CVE-2025-54590?
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-2025-54590?
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-2025-54590?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-54590 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.