CVE-2026-63671: nuxt-content mdc · Cross-site Scripting
Affects nuxt-content mdcSource CVE Database V5
Not known to be exploited · CVSS 8.1 High : upgrade to 0.22.1 soon.
Data as of 31 Oct 2026, 20:20 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.22.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Upgrade mdc and nuxt-content/mdc to 0.22.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nuxt-contentmdc | Affected
| Fixed in
|
GitHubnuxt-content/mdcpkg:github/nuxt-content/mdcOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to nuxt-content mdc version 0.22.1 or later, where this vulnerability is fixed. No additional mitigation is required once the update is applied.
Description
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.
References
- github.com/nuxt-content/mdc/security/advisories/GHSA-mxm6-v9r6-r94c (opens in a new tab)
- github.com/nuxt-content/mdc/pull/491 (opens in a new tab)
- github.com/nuxt-content/mdc/commit/61d636c2983f021288e4fc5c4006733b38cf0d53 (opens in a new tab)
- github.com/nuxt-content/mdc/releases/tag/v0.22.1 (opens in a new tab)