CVE-2026-84394

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Source
https://cve.org/CVERecord?id=CVE-2026-84394
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84394.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-84394
Aliases
  • GHSA-58mr-gqgx-xq4g
Downstream
Published
2026-09-02T20:25:35.399Z
Modified
2026-09-06T03:47:03.782450138Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
fast-uri vulnerable to host confusion via an unclosed bracket in the URI authority
Details

fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an error. A host that starts with an opening bracket but does not end with a closing bracket 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 the HTTP clients built on it resolve the same string to a different host. An application that reads the parsed host to make a host decision, such as an SSRF denylist, a redirect allowlist, or proxy routing, and then passes the original URL to an HTTP client evaluates its policy against a string that is not the host the request reaches. The same host is carried through normalize, equal, and resolve. This affects fast-uri versions 2.4.5, 3.1.6, and 4.1.3, and is fixed in 2.4.6, 3.1.7, and 4.1.4, where parse() reports a malformed host for any host that contains a bracket but is not a valid IPv6 literal.

Database specific 
{
    "cwe_ids": [
        "CWE-436"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84394.json",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "2.4.5"
                },
                {
                    "fixed": "2.4.6"
                },
                {
                    "introduced": "3.1.6"
                },
                {
                    "fixed": "3.1.7"
                },
                {
                    "introduced": "4.1.3"
                },
                {
                    "fixed": "4.1.4"
                }
            ]
        }
    ],
    "cna_assigner": "openjs"
}
References

Affected packages

Git / github.com/fastify/fast-uri

Affected ranges

Type
GIT
Repo
https://github.com/fastify/fast-uri
Events
Introduced
21e274eb54bc738748f66746f4ec1c1e4f919413
Last affected
4e99790cadffc4b4fdaef9912cb503b328505be0
Database specific
Show details 
{
    "cpe": [
        "cpe:2.3:a:openjsf:fast-uri:2.4.5:*:*:*:*:node.js:*:*",
        "cpe:2.3:a:openjsf:fast-uri:3.1.6:*:*:*:*:node.js:*:*",
        "cpe:2.3:a:openjsf:fast-uri:4.1.3:*:*:*:*:node.js:*:*"
    ],
    "source": "CPE_STRING",
    "extracted_events": [
        {
            "introduced": "2.4.5"
        },
        {
            "last_affected": "2.4.5"
        },
        {
            "introduced": "3.1.6"
        },
        {
            "last_affected": "3.1.6"
        },
        {
            "introduced": "4.1.3"
        },
        {
            "last_affected": "4.1.3"
        }
    ]
}

Affected versions

2.*
2.4.5
3.*
3.1.6
4.*
4.1.3

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84394.json"