Regular Expression Denial Of Service in uri-js

published 2018-06-04 8 y ago modified 2026-06-17 4 mo ago also GHSA-333w-rxj3-f55r , EUVD-2018-0211

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits: 0; none known

uri-js is a module that tries to fully implement RFC 3986. One of these features is validating whether or not a supplied URL is valid or not. To do this, uri-js uses a regular expression, This regular expression is vulnerable to redos. This causes the program to hang and the CPU to idle at 100% usage while uri-js is trying to validate if the supplied URL is valid or not. To check if you're vulnerable, look for a call to `require("uri-js").parse()` where a user is able to send their own input. This affects uri-js 2.1.1 and earlier.

Patch / fix

fixed in 1

npm uri-js 3.0.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-16021 updated 2025-11-21 cvss 4.3

nodejs-uri-js: regular expression denial of service vulnerability in parse method

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.32% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/garycourt/uri-js/issues/12 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	6.8	AV:N/AC:L/Au:S/C:N/I:N/A:C
GitHub	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	uri-js	<3.0.0	3.0.0

Affected products

HackerOne uri-js node module

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-1333 Inefficient Regular Expression Complexity

References

github.com /garycourt/uri-js/issues/12
web, exploit, issue-tracking, third-party-advisory
nodesecurity.io /advisories/100
web, broken-link, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2017-16021
advisory
github.com /advisories/GHSA-333w-rxj3-f55r
advisory
npmjs.com /advisories/100
web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary