fast-uri vulnerable to host confusion via an unclosed bracket in the URI authority — GHSA-58MR-GQGX-XQ4G

Summary

### Impact `fast-uri` accepts a host that contains an unbalanced or misplaced authority bracket (`[` or `]`) without reporting an error. A host that starts with `[` but does not end with `]`, such as `[@127.0.0.1`, is neither validated as an IP literal nor canonicalized as a domain name, so `parse()` returns it as the host with `error` undefined, while Node's `URL` (and `http.get`, `axios`, `got`, and other clients…

Timeline

Published by source

2026-09-28

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 7.5 out of 10.
• Reported EPSS value: 0.0038.
• Review exposure for the affected product or family: npm: fast-uri.

Product

npm: fast-uri

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-58MR-GQGX-XQ4G

Source

GitHub

Vendor

GitHub

Published by source

2026-09-28

Last source activity

2026-09-28

Additional identifiers

CVE-2026-84394

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.