vulnerability / NVI-00013212 / Revision 2
fast-uri vulnerable to authority injection via an unvalidated port in serialize
GitHub lists this reviewed advisory for fast-uri, fast-uri, fast-uri. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
7.5 HIGH (3.1)
ce714d77-add3-4f53-aff5-83d477b104bb severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
fast-uri
source listed< 2.4.6
### 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 39
fast-uri
source listed>= 3.0.0, < 3.1.7
### 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 39
fast-uri
source listed>= 4.0.0, < 4.1.4
### 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 39
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-qw65-cvwx-89v3 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-84292 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.