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UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-110180

An application that enforces host-based policy such as denylists, loopback filtering, redirect validation, or outbound proxy routing on one representation can then see the canonical host diverge from what it checked, allowing traffic to be steered to an…

MEDIUM 4.8EPSS 0.26%

Does this matter?

Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.

Description

fast-uri is a dependency-free RFC 3986 URI parser and serializer for Node.js. In versions from 2.4.2 through 2.4.7, from 3.1.3 through 3.1.8, and from 4.0.1 through 4.2.2, for HTTP-family schemes the canonicalizeHost() function passes the parsed host to the WHATWG URL parser and adopts its hostname without checking that the parser consumed the entire input as a host, so the authority can be silently rewritten: data before an at-sign is dropped and tab, carriage-return, and line-feed characters are stripped, with no error reported. An application that enforces host-based policy such as denylists, loopback filtering, redirect validation, or outbound proxy routing on one representation can then see the canonical host diverge from what it checked, allowing traffic to be steered to an unintended destination. The issue is fixed in fast-uri 2.4.8, 3.1.9, and 4.2.3, and users should upgrade to one of these versions or later. As a workaround, reject an authority that contains more than one at-sign or any tab, carriage-return, or line-feed before calling fast-uri, or treat any non-empty parse error as fatal and compare hosts only from the same parse result.

CVSS 3.1
4.8 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
0.26% probability · 17th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20, CWE-436
Source
ce714d77-add3-4f53-aff5-83d477b104bb
EPSS trend
0%3%5%20 October 2026: 0.21%26 October 2026: 0.26%20 October 202626 October 2026

EPSS moved from 0.2% on 20 October 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.