CVE-2026-63671

8.1 HIGHpublic exploit available

Published 2026-09-16 · Updated 2026-09-18

AI risk analysis

Summary: The flaw allows an attacker to inject executable JavaScript via SVG xlink:href, leading to potential code execution in the page origin.
Exploitability: Exploitation is moderately hard as it requires crafting a specific SVG xlink:href with a javascript: URL, and the attacker must be able to inject untrusted Markdown content.
Blast radius: If exploited, this could lead to full compromise of the affected web application, allowing an attacker to execute arbitrary JavaScript in the context of the victim’s browser session.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to version 0.22.1 or later.

rcewebmarkdownsvgxlink:href

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD 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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Weaknesses

CWE-79, CWE-184

Public exploit & PoC references

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.