CVE-2021-39199
CRITICALDescription
remark-html is an open source nodejs library which compiles Markdown to HTML. In affected versions the documentation of remark-html has mentioned that it was safe by default. In practice the default was never safe and had to be opted into. That is, user input was not sanitized. This means arbitrary HTML can be passed through leading to potential XSS attacks. The problem has been patched in 13.0.2 and 14.0.1: `remark-html` is now safe by default, and the implementation matches the documentation. On older affected versions, pass `sanitize: true` if you cannot update.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 61% of all known CVEs.
References
Related Vulnerabilities
Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-11022 | Medium | 6.9 | 99% | - | Fix |
| CVE-2019-3929 | Critical | 9.8 | 99% | KEV | Fix |
| CVE-2020-9496 | Medium | 6.1 | 99% | - | - |
| CVE-2023-28341 | Medium | 6.1 | 99% | - | Fix |
| CVE-2018-12998 | Medium | 6.1 | 98% | - | - |
| CVE-2025-4123 | High | 7.6 | 98% | - | Fix |
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Markdown
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.