XSS in Remark Remark-Html
CVE-2021-39199
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.011 (63.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 63.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Remark Remark-Html
- Remarkjs Remark-Html — versions >= 14.0.0, < 14.0.1, < 13.0.2
Weakness classification (CWE)
References
- github.com/remarkjs/remark-html/security/advisories/GHSA-9q5w-79cv-947m (Patch, Third Party Advisory)
- github.com/remarkjs/remark-html/commit/b75c9dde582ad87ba498e369c033dc8a350478c1 (Patch, Third Party Advisory)
- github.com/remarkjs/remark-html/releases/tag/14.0.1 (Patch, Third Party Advisory, Release Notes)
- www.npmjs.com/package/remark-html (Product, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-39199?
- CVE-2021-39199 is a critical-severity vulnerability in Remark Remark-Html, classified under Cross-site Scripting. CVSS score: 10.0/10. Published 2021-09-07.
- How severe is CVE-2021-39199?
- Critical severity. CVSS v3 base score is 10.0 out of 10.