fast-uri vulnerable to authority injection via an unvalidated port in serialize — GHSA-QW65-CVWX-89V3

Summary

### Impact `fast-uri` serializes the `port` component of a URI without validating it. When recomposing the authority, `fast-uri` escapes the userinfo and host components but concatenates the port verbatim, so a `port` value that is not a sequence of digits can inject authority delimiters. For example, serializing a component whose `port` is `@127.0.0.1:8124` produces `http://trusted.example:@127.0.0.1:8124/app`,…

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-QW65-CVWX-89V3

Source

GitHub

Vendor

GitHub

Published by source

2026-09-28

Last source activity

2026-09-28

Additional identifiers

CVE-2026-84292

Curated by

hlukh.ch

Related advisories and connections

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