Nuxtにクロスサイトスクリプティング（XSS）の脆弱性（CVE-2026-114130）

## Impact An application that renders `<NuxtLink :to="...">` with a value it does not control can be made to render an anchor whose `href` executes script in the application's origin when clicked. This is an incomplete fix for [GHSA-934w-87qh-qr26](https://github.com/nuxt/nuxt/security/advisories/GHSA-934w-87qh-qr26) (CVE-2026-53722). It only affects applications running without a `pages/` directory, where `pages` resolves to `false` and Nuxt registers its own router in place of vue-router. Applications using vue-router are not affected. Prefixing `javascript:` with an ASCII C0 control character, for example `%01`, meant the value was not recognised as having a protocol. It was classified as an internal route and so never reached the protocol check added in GHSA-934w-87qh-qr26, and the router used for `pages: false` passed it through to the rendered `href` unchanged. Browsers strip the leading control character and run the result as a script URL. Both `<NuxtLink custom>` and the default anchor are affected, and the `href` is present in the server-rendered HTML. ## Mitigating factors - The application must have `pages` disabled (no `pages/` directory, or `pages: false`). - The application must bind untrusted input to `:to`. - A victim must click the rendered link. ## Affected versions `nuxt` `<4.6.0`, including all Nuxt 3 releases. Versions before `4.4.7` and `3.21.7` are also affected by GHSA-934w-87qh-qr26. ## Patches Fixed in `nuxt@4.6.0`. Nuxt 3 reached end of life on 31 July 2026 and will not receive a fix. Anchor `href` values are now checked for script-capable protocols wherever they are rendered, including the router used when `pages` is disabled. Protocol detection also moved to the platform `URL` parser, so a URL is classified the same way the browser will read it. ## Workarounds Upgrade to `nuxt@4.6.0` or later. If you cannot upgrade, including on Nuxt 3, validate values before binding them to `:to`, for example by rejecting anything that is not a path beginning with a single `/`.

Nuxt is an open-source web development framework for Vue.js. Prior to 4.6.0, an incomplete fix for CVE-2026-53722 allows an application with pages disabled to render a script-capable URL through NuxtLink when attacker-controlled input bound to to is prefixed with an ASCII C0 control character. The no-pages router classifies the value as an internal route before the earlier protocol check and passes it to the rendered anchor href; browsers remove the leading control character and interpret the remaining javascript: URL. The default anchor and NuxtLink custom output are affected, the unsafe href is present in server-rendered HTML, and a victim must click the link for script to execute in the application's origin. This issue is fixed in version 4.6.0.