Login.

Vulnerability details

7.5/10
CVSS 3.1
GHSA-f65p-4m7j-42xc
resolved Published 2026-09-02 Updated 2026-09-02
GitHub Advisory
Vulnerability Data from Dependency-Track
Affected versions
Score
7.5 CVSS 3.1 GITHUB CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Description
### Impact `fast-uri` does not validate the complete RFC 3986 grammar for bracketed IPv6 literals, so a malformed literal with invalid trailing text is silently truncated to a different valid IPv6 address with no error reported. For example, `normalize('http://[::not-valid]/private')` returns `http://[::]/private`, and `[fc00::not-hex]` and `[fe80::not-hex]` collapse to `[fc00::]` and `[fe80::]`. An application that normalizes an untrusted URL before an outbound request, redirect, or host-policy check can be routed to a local or private address such as loopback (`::1`), unique-local, or link-local. Because `parse().error` is unset for these inputs, checking it does not protect the consumer. ### Patches Upgrade to `fast-uri` 2.4.5, 3.1.6, or 4.1.3. Malformed IPv6 literals are now rejected with a host error instead of being normalized to a valid address. ### Workarounds Reject untrusted URLs whose host is a bracketed IPv6 literal before passing them to `fast-uri`, or route outbound requests against an explicit allowlist of addresses rather than trusting the normalized host.
Same vulnerability as
CVE-2026-75975 resolved according to EUVD-2026-64772
Analysis Read only
The analysis can only be edited by the BlueMind security teams: log in.

CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE data may be incomplete, delayed, or inaccurate. This website and all information provided are offered on an “as is” basis without warranties of any kind. This site is not affiliated with, endorsed by, or sponsored by the CVE Program or The MITRE Corporation.

This site uses data from the National Vulnerability Database (NVD), obtained through Dependency-Track, but is not endorsed or certified by the NVD or the National Institute of Standards and Technology (NIST). NVD data may be incomplete, delayed, or inaccurate.

CVSS (Common Vulnerability Scoring System) is owned and managed by FIRST.Org, Inc. and used by permission. The links on CVSS vectors open the FIRST CVSS calculators (CVSS 3.0, 3.1 and 4.0), or the NVD calculator for CVSS 2.0. This site is not affiliated with, endorsed by, or sponsored by FIRST.

GitHub is a trademark of GitHub, Inc. GHSA identifiers and advisory data come from the GitHub Advisory Database, licensed under CC-BY 4.0. GHSA data may be incomplete, delayed, or inaccurate. This site is not affiliated with, endorsed by, or sponsored by GitHub, Inc.

Source of the EUVD data: European Vulnerability Database (EUVD), © European Union Agency for Cybersecurity (ENISA), reused with acknowledgement of the source as provided by the ENISA legal notice and IPR policy. Changes: CVEManager does not display the EUVD records as such; it uses their aliases to link the CVE and GHSA identifiers designating the same vulnerability. EUVD data may be incomplete, delayed, or inaccurate. This site is not affiliated with, endorsed by, or sponsored by ENISA or the European Union.