Sanitization bypass using HTML Entities in marked
Affected versions of marked are susceptible to a cross-site scripting vulnerability in link components when sanitize:true is configured.
Proof of Concept
This flaw exists because link URIs containing HTML entities get processed in an abnormal manner. Any HTML Entities get parsed on a best-effort basis and included in the resulting link, while if that parsing fails that character is omitted.
For example:
A link URI such as
javascript֍ocument;alert(1)Renders a valid link that when clicked will execute alert(1).
Recommendation
Update to version 0.3.6 or later.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | marked | < 0.3.6 | 0.3.6 |
References
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- npm
- Package
marked- Disclosed
- 18.02.2019
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-vfvf-mqq8-rwqc - CC BY 4.0
Vulnerability history: marked
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 13
- First → latest
- 10.2017 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 5
- Medium 7
- Low 1
Disclosures per year
- 2017: 2
- 2018: 2
- 2019: 2
- 2020: 2
- 2021: 1
- 2022: 2
- 2023: 0
- 2024: 0
- 2025: 1
- 2026: 1
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Sanitization bypass using HTML Entities in marked this entry
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