@nuxt/ui: UAuthForm / UForm SSR markup omits `method`, leaking credentials via GET if submitted before hydration
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- Information disclosure
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub. Impact type from CWE-200.
Summary
### Summary `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: ```vue <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: 1. Create a minimal Nuxt app with a `UAuthForm`. 2. Build for production and visit in a browser with network throttling at 4G or slower. 3. Enter credentials. 4. 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 `Referer` header 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`.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | @nuxt/ui (npm) | before 4.8.1 | 4.8.1 | Patch available | GHSA-gj2h-2fpw-fhv9 |
- @nuxt/ui (npm) Vendor— Affected before 4.8.1 Fixed in 4.8.1 Patch available GHSA-gj2h-2fpw-fhv9
Remediation
- Fix · GHSA-gj2h-2fpw-fhv9 @nuxt/ui (npm) Fixed in 4.8.1 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-gj2h-2fpw-fhv9
References
Sources
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