yuin/goldmark · Security

goldmark vulnerable to Cross-site Scripting (XSS)

GHSA ID
GHSA-c97m-vxhj-p7j6
CVE ID
CVE-2026-5160
Severity
medium
Published
Updated
CVSS
6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v3
6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4
5.1 · 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

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.

CWEs

References