fast-uri vulnerable to authority injection via an unvalidated port in serialize
### 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`, 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 (for example a fixed host from configuration and a port taken from user input or a service record). The same path is reachable through `serialize()`, `normalize()`, and `equal()` in their object forms. A `port` obtained from `parse()` is always digits and is not affected. ### Patches This vulnerability has been patched in fast-uri `4.1.4`, `3.1.7`, and `2.4.6`. `recomposeAuthority` now rejects any port that is not `*DIGIT` per RFC 3986. All users should upgrade. ### Workarounds If upgrading is not immediately possible, validate the `port` value against the RFC 3986 grammar (digits only) before passing a component to `serialize()`, `normalize()`, or `equal()`, and reject anything else, for example `if (!/^\d*$/.test(String(port))) t
GHSA-qw65-cvwx-89v3
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-qw65-cvwx-89v3
fast-uri
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.4.6
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
fast-uri
Source reference: /affected/1/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 3.1.7
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
fast-uri
Source reference: /affected/2/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 4.1.4
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.4.6"
}
]
}
],
"package": {
"name": "fast-uri",
"purl": "pkg:npm/fast-uri",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-qw65-cvwx-89v3/GHSA-qw65-cvwx-89v3.json"
}
},
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.1.7"
}
]
}
],
"package": {
"name": "fast-uri",
"purl": "pkg:npm/fast-uri",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-qw65-cvwx-89v3/GHSA-qw65-cvwx-89v3.json"
}
},
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.1.4"
}
]
}
],
"package": {
"name": "fast-uri",
"purl": "pkg:npm/fast-uri",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-qw65-cvwx-89v3/GHSA-qw65-cvwx-89v3.json"
}
}
]- Related CVEs
- CVE-2026-84292
Source reference:
/aliases
Publisher severity
high
Source reference: /database_specific/severity
- Event
- #23690 · Revision 1
- Added to Heist Feed
- Publisher date