vue-i18n's escapeParameterHtml does not prevent DOM-based XSS through its tag attributes
Date: 2025-07
Affected: npm/petite-vue-i18n, npm/petite-vue-i18n, npm/@intlify/vue-i18n-core
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2025-53892
CWE: CWE-79

### Summary The escapeParameterHtml: true option in Vue I18n is designed to protect against HTML/script injection by escaping interpolated parameters. However, this setting fails to prevent execution of certain tag-based payloads, such as `<img src=x onerror=...>`, if the interpolated value is inserted inside an HTML context using v-html. This may lead to a DOM-based XSS vulnerability, even when using escapeParameterHtml: true, if a translation string includes minor HTML and is rendered via v-html. ### Details When escapeParameterHtml: true is enabled, it correctly escapes common injection points. However, it does not sanitize entire attribute contexts, which can be used as XSS vectors via: `<img src=x onerror=alert(1)> ` ### PoC In your Vue I18n configuration: ``` const i18n = createI18n({ escapeParameterHtml: true, messages: { en: { vulnerable: 'Caution: <img src=x onerror="{payload}">' } } }); ``` Use this interpolated payload: `const payload = '<script>alert("xss")</script>';` Render the translation using v-html (even not using v-html): `<p v-html="$t('vulnerable', { payload })"></p> ` Expected: escaped content should render as text, not execute. Actual: script executes in some environments (or the payload is partially parsed as HTML). ### Impact This creates a DOM-based Cross-Site Scripting (XSS) vulnerability despite enabling a security option (escapeParameterHtml) .


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