CVE intelligence and bounded remediation

CVE-2020-26291 — URI.js is a javascript URL mutation library (npm package urijs)

Medium CVSS 6.5

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.]

Severity
Medium
CVSS
6.5 (3.1)
Published
2020-12-31
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-20

Affected products

  • uri.js_project / uri.js

Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

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