Critical severity10.0NVD Advisory· Published Sep 7, 2021· Updated Jun 17, 2026
CVE-2021-39199
CVE-2021-39199
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
remark-htmlnpm | < 13.0.2 | 13.0.2 |
remark-htmlnpm | >= 14.0.0, < 14.0.1 | 14.0.1 |
Affected products
3- Range: >= 14.0.0, < 14.0.1
Patches
Vulnerability mechanics
References
6- github.com/remarkjs/remark-html/commit/b75c9dde582ad87ba498e369c033dc8a350478c1nvdPatchThird Party AdvisoryWEB
- github.com/remarkjs/remark-html/releases/tag/14.0.1nvdPatchRelease NotesThird Party AdvisoryWEB
- github.com/remarkjs/remark-html/security/advisories/GHSA-9q5w-79cv-947mnvdPatchThird Party AdvisoryWEB
- github.com/advisories/GHSA-9q5w-79cv-947mghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2021-39199ghsaADVISORY
- www.npmjs.com/package/remark-htmlnvdProductThird Party AdvisoryWEB
News mentions
0No linked articles in our index yet.