Disclosure summary
fast-uri serializes the port component of a URI without validating it. When recomposing the authority, the userinfo and host components are escaped but the port is concatenated verbatim, so a port value that is not a sequence of digits can inject authority delimiters, demoting the intended host to userinfo and pointing the authority at an attacker-controlled host. Both fast-uri and Node's URL read the result back as the attacker's host with no error, so re-validating the built URI does not catch it. This affects applications that build URIs from parts and assign untrusted data to the port component through the serialize, normalize, or equal functions in their object forms. The issue affects fast-uri versions before 2.4.6, from 3.0.0 before 3.1.7, and from 4.0.0 before 4.1.4. It is fixed in 2.4.6, 3.1.7, and 4.1.4, where recomposeAuthority rejects any port that is not a digit sequence per RFC 3986.
Source-reported weakness categories
CWE-116
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-84292
Open original source · Updated Oct 06, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| openjsf | fast-uri | * {"versionStartIncluding":"4.0.0","versionEndExcluding":"4.1.4"} |
Original records & references
- NIST NVD record
- CVE Program record
- cna.openjsf.org — Vendor Advisory
- github.com — Mitigation, Vendor Advisory
PUBLISHED 2026-09-02T16:17:39-04:00
MODIFIED 2026-10-06T18:10:00-04:00
INGESTED 2026-10-10T20:25:12-04:00