---
id: CVE-2026-63671
title: >-
  MDC is a tool to take regular Markdown and write documents interacting deeply
  with a Vue component
summary: >-
  MDC is a tool to take regular Markdown and write documents interacting deeply
  with a Vue component. Prior to 0.22.1, @nuxtjs/mdc uses parseMarkdown with
  allowDangerousHtml enabled by default and relies on validateProps,
  validateProp, and…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N'
cwe:
  - CWE-79
  - CWE-184
vendor: nuxt-content
product: mdc
affected:
  - mdc < 0.22.1
patched:
  - '@nuxtjs/mdc 0.22.1'
published: '2026-09-16'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63671'
references:
  - url: >-
      https://github.com/nuxt-content/mdc/commit/61d636c2983f021288e4fc5c4006733b38cf0d53
    label: security-advisories@github.com
  - url: 'https://github.com/nuxt-content/mdc/pull/491'
    label: security-advisories@github.com
  - url: 'https://github.com/nuxt-content/mdc/releases/tag/v0.22.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c
    label: security-advisories@github.com
  - url: >-
      https://github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c
    label: security-advisories@github.com
  - url: >-
      https://github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c
    label: security-advisories@github.com
  - url: >-
      https://github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c
    label: security-advisories@github.com
  - url: >-
      https://github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63671'
  - url: 'https://github.com/advisories/GHSA-mxm6-v9r6-r94c'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - npm
epss: 0.00474
epssPercentile: 0.38381
aliases:
  - GHSA-mxm6-v9r6-r94c
ecosystem: npm
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T17:53:48.238587Z'
ingestedAt: '2026-09-16T14:57:28.054Z'
---

## Overview

MDC is a tool to take regular Markdown and write documents interacting deeply with a Vue component. Prior to 0.22.1, @nuxtjs/mdc uses parseMarkdown with allowDangerousHtml enabled by default and relies on validateProps, validateProp, and unsafeLinkPrefix to remove executable URLs from untrusted Markdown. validateProp checks only attributes named href or src, allowing an SVG xlink:href value represented as xLinkHref to retain a javascript: URL that executes in the page origin when selected. The data:text/html denylist entries are also compared against url.protocol, which is only data:, so an iframe src containing data:text/html survives sanitization and executes in an opaque origin when loaded. Plain href javascript: URLs, srcdoc, object, script, and base elements are already blocked, making these two paths specific sibling gaps in the sanitizer. This issue is fixed in version 0.22.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-63671)

Affected packages:

- `@nuxtjs/mdc < 0.22.1`

Patched in:

- `@nuxtjs/mdc 0.22.1`

Source: https://github.com/advisories/GHSA-mxm6-v9r6-r94c