Cross-site Scripting (XSS) in github.com/yuin/goldmark
Cross-site Scripting (XSS) in github.com/yuin/goldmark
02 / AFFECTED SOFTWARE
Affected packages
98 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
Cross-site Scripting (XSS) in github.com/yuin/goldmark
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.
05 / REFERENCES
Further evidence
- https://github.com/yuin/goldmark
- https://github.com/yuin/goldmark/commit/cb46bbc4eca29d55aa9721e04ad207c23ccc44f9
- https://nvd.nist.gov/vuln/detail/CVE-2026-5160
- https://security.snyk.io/vuln/SNYK-GOLANG-GITHUBCOMYUINGOLDMARKRENDERERHTML-15838406
- https://github.com/advisories/GHSA-c97m-vxhj-p7j6
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5160.json