CVE-2020-26291

Hostname spoofing in URI.js

MEDIUM
6.5
CVSS Score
Published: December 30, 2020 at 11:40 PM UTC
Updated: June 17, 2026 at 03:08 AM UTC
2 products affected across 2 vendorsUri.jsURI.js

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Severity
MEDIUM6.5
Exploit prediction
EPSS 2%

Description

URI.js is a javascript URL mutation library (npm package urijs). In URI.js before version 1.19.4, the hostname can be spoofed by using a backslash (`\`) character followed by an at (`@`) character. If the hostname is used in security decisions, the decision may be incorrect. Depending on library usage and attacker intent, impacts may include allow/block list bypasses, SSRF attacks, open redirects, or other undesired behavior. For example the URL `https://expected-example.com\@observed-example.com` will incorrectly return `observed-example.com` if using an affected version. Patched versions correctly return `expected-example.com`. Patched versions match the behavior of other parsers which implement the WHATWG URL specification, including web browsers and Node's built-in URL class. Version 1.19.4 is patched against all known payload variants. Version 1.19.3 has a partial patch but is still vulnerable to a payload variant.]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.19.4
Affected range stops below 1.19.4, so it looks safe — our inference, not a vendor statement
v < 1.19.4
Affected range stops below 1.19.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20

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