CVE-2019-16201

Name: CVE-2019-16201
Creator: NVD / NIST
Published: 2019-11-26T18:15:15.1+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 5.09%

Last modified Jun 17, 2026

CVE-2019-16201 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. WEBrick::HTTPAuth::DigestAuth in Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 has a regular expression Denial of Service cause by looping/backtracking. A victim must expose a WEBrick server that uses DigestAuth to the Internet or a untrusted network.. EPSS estimates a 5.09% chance of exploitation in the next 30 days.

Description

WEBrick::HTTPAuth::DigestAuth in Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 has a regular expression Denial of Service cause by looping/backtracking. A victim must expose a WEBrick server that uses DigestAuth to the Internet or a untrusted network.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

5.09%

91.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-287

Affected Software

Vendor	Product	Versions
Ruby-Lang	Ruby	>= 2.4.0, <= 2.4.7
Ruby-Lang	Ruby	>= 2.5.0, <= 2.5.6
Ruby-Lang	Ruby	>= 2.6.0, <= 2.6.4
Debian	Debian Linux	8.0

References

Timeline

Published: Nov 26, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-16201?

How severe is CVE-2019-16201?

CVE-2019-16201 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 5.09% probability of exploitation in the next 30 days.

How do I fix CVE-2019-16201?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-16201?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST