Versions of the package github.com/yuin/goldmark/renderer/html before 1.7.17 are vulnerable to Cross-site Scripting (XSS) due to improper ordering of URL validation and normalization. The renderer validates link destinations using a prefix-based check (IsDangerousURL) before resolving HTML entities. This allows an attacker to bypass protocol filtering by encoding dangerous schemes using HTML5 named character references. For example, a payload such as javascript:alert(1) is not recognized as dangerous during validation, leading to arbitrary script execution in the context of applications that render the URL.

Project Subscriptions

Vendors Products
Goldmark Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 17 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Title Cross-site scripting via URL validation bug in Goldmark HTML renderer github.com/yuin/goldmark/renderer/html: github.com/yuin/goldmark/renderer/html: Cross-site Scripting due to improper URL validation
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 15 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Yuin
Yuin goldmark
Vendors & Products Yuin
Yuin goldmark

Wed, 15 Apr 2026 14:00:00 +0000

Type Values Removed Values Added
Title Cross-site scripting via URL validation bug in Goldmark HTML renderer

Wed, 15 Apr 2026 05:45:00 +0000

Type Values Removed Values Added
Description Versions of the package github.com/yuin/goldmark/renderer/html before 1.7.17 are vulnerable to Cross-site Scripting (XSS) due to improper ordering of URL validation and normalization. The renderer validates link destinations using a prefix-based check (IsDangerousURL) before resolving HTML entities. This allows an attacker to bypass protocol filtering by encoding dangerous schemes using HTML5 named character references. For example, a payload such as javascript:alert(1) is not recognized as dangerous during validation, leading to arbitrary script execution in the context of applications that render the URL.
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: snyk

Published:

Updated: 2026-04-15T18:07:10.025Z

Reserved: 2026-03-30T14:14:48.647Z

Link: CVE-2026-5160

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-15T06:16:13.860

Modified: 2026-04-15T06:16:13.860

Link: CVE-2026-5160

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-15T05:00:01Z

Links: CVE-2026-5160 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-15T14:53:30Z

Weaknesses