CVE-2026-76172 fast-uri vulnerable to host confusion via percent-encoded scheme normalization

fast-uri is a URI parser for Node.js. During parsing it runs a legacy decoding pass over the scheme component and never re-escapes the result, and serialization writes the scheme back out verbatim, unlike the host component which is re-escaped. As a result an input whose scheme carries...

CVE-2026-75931

fast-uri , a URI parser for the Node.js ecosystem, is vulnerable to host confusion and policy bypass (CVSS 3.1: 7.5 HIGH ). The root cause is that the host is canonicalized to ASCII form only when the input carries an explicit scheme; scheme-relative references (host preceded by //) are returned ...

EUVD-2026-64758

fast-uri is a URI parser for Node.js. It canonicalizes a host to its ASCII form only when the input carries an explicit scheme, so a scheme-relative reference such as a host preceded by two slashes is returned with its host verbatim and no error set. As a result fast-uri's own entry points disagr...

fast-uri vulnerable to host confusion via backslash authority introducer

Impact fast-uri v4.1.1 and earlier require a literal // to recognize a URI authority, so a reference that uses \, /, or / as the authority introducer in place of //, after an optional scheme is parsed with no authority: the sequence and everything after it fold into the path. Node's native...

NPM: fast-uri vulnerable to host confusion via backslash authority introducer

NPM: fast-uri vulnerable to host confusion via backslash authority introducer vulnerability discovered by ? in WordPress Npm fast-uri versions 2.4.4...

GHSA-7P8R-X3MC-P8W7 fast-uri vulnerable to host confusion via backslash authority introducer

Impact fast-uri v4.1.1 and earlier require a literal // to recognize a URI authority, so a reference that uses \, /, or / as the authority introducer in place of //, after an optional scheme is parsed with no authority: the sequence and everything after it fold into the path. Node's native...

fast-uri: fast-uri: Host confusion vulnerability via backslash in URI authority

A flaw was found in fast-uri. This vulnerability arises because fast-uri incorrectly parses Uniform Resource Identifiers URIs when a backslash is used in place of a forward slash to introduce the authority component. This discrepancy with Node's native WHATWG URL parser can lead to host confusion...

fast-uri: fast-uri: Host confusion vulnerability via backslash in URI authority

A flaw was found in fast-uri. This vulnerability arises because fast-uri incorrectly parses Uniform Resource Identifiers URIs when a backslash is used in place of a forward slash to introduce the authority component. This discrepancy with Node's native WHATWG URL parser can lead to host confusion...

CVE-2026-18446 fast-uri vulnerable to host confusion via backslash authority introducer

fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it backslash backslash, forward slash backslash, or backslash forward slash is parsed with no authority and folds into th...

CVE-2026-18446 fast-uri vulnerable to host confusion via backslash authority introducer

fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it backslash backslash, forward slash backslash, or backslash forward slash is parsed with no authority and folds into th...

CVE-2026-18446 fast-uri vulnerable to host confusion via backslash authority introducer

fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it backslash backslash, forward slash backslash, or backslash forward slash is parsed with no authority and folds into th...

CVE-2026-18446

CVE-2026-18446 affects the fast-uri library prior to versions 4.1.2, 3.1.5, and 2.4.4 . A backslash-based introducer can substitute for a literal double forward slash required to recognize a URI authority, causing fast-uri to misparse the host while Node’s WHATWG URL parser treats backslashes dif...

fast-uri vulnerable to host confusion via literal backslash authority delimiter

Impact fast-uri v4.1.0 and earlier do not treat a literal backslash U+005C as an authority delimiter. Node's native WHATWG URL used by fetch, undici, and Node's http/https clients normalizes \ to / for special schemes http, https, ws, wss, ftp, file, so the two parsers extract different hosts fro...

NPM: fast-uri vulnerable to host confusion via literal backslash authority delimiter

NPM: fast-uri vulnerable to host confusion via literal backslash authority delimiter vulnerability discovered by ? in WordPress Npm fast-uri versions = 2.3.1, = 2.4.2...

GHSA-4C8G-83QW-93J6 fast-uri vulnerable to host confusion via failed IDN canonicalization

Impact fast-uri versions = 2.3.1, = 4.0.0 fail to canonicalize Unicode/IDN hostnames for HTTP-family URLs. The IDN conversion path calls URL.domainToASCII... on the global WHATWG URL constructor, where that helper does not exist. The resulting TypeError is silently routed into parsed.error, but...

fast-uri vulnerable to host confusion via failed IDN canonicalization

Impact fast-uri versions = 2.3.1, = 4.0.0 fail to canonicalize Unicode/IDN hostnames for HTTP-family URLs. The IDN conversion path calls URL.domainToASCII... on the global WHATWG URL constructor, where that helper does not exist. The resulting TypeError is silently routed into parsed.error, but...

NPM: fast-uri vulnerable to host confusion via failed IDN canonicalization

NPM: fast-uri vulnerable to host confusion via failed IDN canonicalization vulnerability discovered by ? in WordPress Npm fast-uri versions = 2.3.1, 2.4.2...

guzzlehttp/psr7: Host Confusion via Weak URI Host Validation

Impact guzzlehttp/psr7 did not reject URI host components containing authority delimiters /, ?, , @, or , an embedded port such as host:8080, or IPv6 brackets that do not frame the host such as ::1 or ::1. Uri::assertValidHost rejected only control characters, so these malformed hosts were...

CVE-2026-16221

CVE-2026-16221 affects fast-uri versions 2.3.1–4.1.0 (including 3.x up to 3.1.3 and 2.x up to 2.4.2). The root cause is that a literal backslash (U+005C) is not treated as an authority delimiter, causing two URL parsers to extract different hosts from the same input. Node’s native WHATWG URL pars...

CVE-2026-16221 fast-uri vulnerable to host confusion via literal backslash authority delimiter

Impact: fast-uri versions from 2.3.1 through 4.1.0 including the 3.x line up to 3.1.3 and the 2.x line up to 2.4.2 do not treat a literal backslash character U+005C as an authority delimiter. Node's native WHATWG URL parser, used by fetch, undici, and Node's http and https clients, normalizes the...