CVE-2025-54590

CVE-2025-54590 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

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.

Frequently asked questions

What is CVE-2025-54590?
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.
How severe is CVE-2025-54590?
CVE-2025-54590 has a CVSS 4.0 base score of 6.9, rated medium severity.
Is CVE-2025-54590 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-54590?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-54590 have an EU (EUVD) identifier?
Yes. CVE-2025-54590 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-23378.
When was CVE-2025-54590 published?
CVE-2025-54590 was published on 2025-08-01 and last updated on 2026-06-17.

References

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities

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