Cross-site scripting via <NoScript> slot content in Nuxt's head components
Impact
Nuxt's globally registered <NoScript> component (from @unhead/vue head components, re-exported by Nuxt) wrote its default-slot content to the innerHTML of the <noscript> head tag, bypassing the HTML escaping that {{ }} interpolation normally applies in Vue templates.
Applications that placed untrusted, attacker-controllable data inside a <NoScript> slot, for example:
<NoScript>{{ route.query.banner }}</NoScript>
would emit that value unescaped inside <noscript> in the server-rendered HTML. With scripting enabled, the HTML parser treats <noscript> content in <head> under the "in head noscript" insertion mode: any tag other than link, meta, noframes, or style implicitly closes <noscript> and is re-processed in the head. A payload such as <script>...</script> therefore escapes the element and executes in the document context.
Sibling head components (<Style>, <Title>) were not affected because they already routed slot text through the safe textContent path.
Affected versions
All currently supported versions of nuxt that ship the <NoScript> global component.
Patches
Fixed in nuxt@4.4.7 (commit 4b054e9d) and backported to nuxt@3.21.7 (commit 7fea9fd6). The fix escapes <NoScript> slot content with escapeHtml from @vue/shared and writes it to textContent rather than innerHTML. Slot content is now rendered as text; intentional markup inside <NoScript> is no longer parsed as HTML.
Workarounds
Until you can upgrade:
- Do not interpolate untrusted input into
<NoScript>slots. Replace<NoScript>{{ x }}</NoScript>with a static string, or sanitise / HTML-escapexat the source. - If you must render dynamic noscript content, write the tag yourself via
useHead({ noscript: [{ textContent: escapedValue }] })after escapingescapedValue.
Credit
Reported to Anthropic's coordinated vulnerability disclosure pipeline by Claude (Anthropic's AI assistant) and triaged by the Anthropic security team. Reference: ANT-2026-4NJYDFFM.
Independently reported by @alcls01111 via GitHub's coordinated disclosure flow (GHSA-8grp-wcq9-925q), closed as a duplicate of this advisory.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | nuxt | >= 4.0.0, < 4.4.7, < 3.21.7 | 4.4.7, 3.21.7 |
References
- https://github.com/nuxt/nuxt/security/advisories/GHSA-m3q2-p4fw-w38m
- https://nvd.nist.gov/vuln/detail/CVE-2026-56317
- https://github.com/nuxt/nuxt/commit/4b054e9d95f8daf366cb144b52782047c511a66e
- https://github.com/nuxt/nuxt/commit/7fea9fd687f1dacbfb63db5fae5839896b017a0e
- https://github.com/nuxt/nuxt
- https://www.vulncheck.com/advisories/nuxt-cross-site-scripting-via-noscript-component-slot-content
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-79- Platform
- npm
- Package
nuxt- Disclosed
- 16.06.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-m3q2-p4fw-w38m - CC BY 4.0
Vulnerability history: nuxt
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 21
- First → latest
- 06.2023 08.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 7
- Medium 8
- Low 4
Disclosures per year
- 2023: 1
- 2024: 2
- 2025: 2
- 2026: 16
-
Cross-site scripting via <NoScript> slot content in Nuxt's head components this entry
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