GHSA-GJ2H-2FPW-FHV9
Vulnerability from github – Published: 2026-07-02 20:16 – Updated: 2026-07-02 20:16Summary
UForm and UAuthForm render a server-side <form> element with no method and no action attribute, relying on a hydrated @submit.prevent handler to intercept submission. If a user submits the form before Vue hydration has attached the handler (autofill plus Enter on a slow network, JS bundle blocked by CSP or CDN failure, etc.), the browser performs the native default: a GET to the current URL with every named field, including <input type="password">, serialised into the query string.
Details
src/runtime/components/Form.vue (around the template's <form> element) emits:
<component
:is="parentBus ? 'div' : 'form'"
:id="formId"
ref="formRef"
:class="ui({ class: [uiProp?.base, props.class] })"
@submit.prevent="onSubmitWrapper"
>
No method, no action. @submit.prevent is the only thing stopping native submission, and it only exists after hydration. UAuthForm composes UForm and inherits the same shape.
The SSR snapshot of UAuthForm (test/components/__snapshots__/AuthForm.spec.ts.snap) shows the rendered markup, with <input type="password" name="password"> inside a <form> that has no method.
Proof of concept
Reported by @nimonian:
- Create a minimal Nuxt app with a
UAuthForm. - Build for production and visit in a browser with network throttling at 4G or slower.
- Enter credentials.
- Submit (or let autofill + Enter fire before hydration).
The URL becomes /login?email=…&password=…. Reproducible deterministically in Playwright by triggering submit immediately on load.
Impact
Any application using UAuthForm (or UForm with credential-shaped fields) as documented. The cleartext password lands in:
- the address bar,
window.history,- the
Refererheader of every same-origin subresource fetched from the resulting URL, - access logs of any reverse proxy, CDN, or WAF that records request URLs.
Patch
Default the rendered <form> to method="post" so the pre-hydration fallback submits as POST rather than GET. Vue's @submit.prevent still intercepts the hydrated case; the attribute only matters in the race window. Applications that explicitly want native GET submission can opt back in by passing method="get".
Credit
Reported by @nimonian. Originally filed as GHSA-92g7-2fpq-hmq8 against nuxt/nuxt; moved here because the affected code lives in @nuxt/ui.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@nuxt/ui"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "4.7.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-200",
"CWE-598"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-02T20:16:12Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\n\n`UForm` and `UAuthForm` render a server-side `\u003cform\u003e` element with no `method` and no `action` attribute, relying on a hydrated `@submit.prevent` handler to intercept submission. If a user submits the form before Vue hydration has attached the handler (autofill plus Enter on a slow network, JS bundle blocked by CSP or CDN failure, etc.), the browser performs the native default: a `GET` to the current URL with every named field, including `\u003cinput type=\"password\"\u003e`, serialised into the query string.\n\n### Details\n\n`src/runtime/components/Form.vue` (around the template\u0027s `\u003cform\u003e` element) emits:\n\n```vue\n\u003ccomponent\n :is=\"parentBus ? \u0027div\u0027 : \u0027form\u0027\"\n :id=\"formId\"\n ref=\"formRef\"\n :class=\"ui({ class: [uiProp?.base, props.class] })\"\n @submit.prevent=\"onSubmitWrapper\"\n\u003e\n```\n\nNo `method`, no `action`. `@submit.prevent` is the only thing stopping native submission, and it only exists after hydration. `UAuthForm` composes `UForm` and inherits the same shape.\n\nThe SSR snapshot of `UAuthForm` (`test/components/__snapshots__/AuthForm.spec.ts.snap`) shows the rendered markup, with `\u003cinput type=\"password\" name=\"password\"\u003e` inside a `\u003cform\u003e` that has no `method`.\n\n### Proof of concept\n\nReported by @nimonian:\n\n1. Create a minimal Nuxt app with a `UAuthForm`.\n2. Build for production and visit in a browser with network throttling at 4G or slower.\n3. Enter credentials.\n4. Submit (or let autofill + Enter fire before hydration).\n\nThe URL becomes `/login?email=\u2026\u0026password=\u2026`. Reproducible deterministically in Playwright by triggering submit immediately on `load`.\n\n### Impact\n\nAny application using `UAuthForm` (or `UForm` with credential-shaped fields) as documented. The cleartext password lands in:\n\n- the address bar,\n- `window.history`,\n- the `Referer` header of every same-origin subresource fetched from the resulting URL,\n- access logs of any reverse proxy, CDN, or WAF that records request URLs.\n\n### Patch\n\nDefault the rendered `\u003cform\u003e` to `method=\"post\"` so the pre-hydration fallback submits as POST rather than GET. Vue\u0027s `@submit.prevent` still intercepts the hydrated case; the attribute only matters in the race window. Applications that explicitly want native GET submission can opt back in by passing `method=\"get\"`.\n\n### Credit\n\nReported by @nimonian. Originally filed as `GHSA-92g7-2fpq-hmq8` against `nuxt/nuxt`; moved here because the affected code lives in `@nuxt/ui`.",
"id": "GHSA-gj2h-2fpw-fhv9",
"modified": "2026-07-02T20:16:12Z",
"published": "2026-07-02T20:16:12Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/nuxt/ui/security/advisories/GHSA-gj2h-2fpw-fhv9"
},
{
"type": "PACKAGE",
"url": "https://github.com/nuxt/ui"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "@nuxt/ui: UAuthForm / UForm SSR markup omits `method`, leaking credentials via GET if submitted before hydration"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.