CVE-2026-118257: Vue I18n: escapeParameter does not prevent XSS through srcdoc in translation messages

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-28 · updated 2026-10-29
Weakness: CWE-79

Description

Vue I18n is the internationalization plugin for Vue.js. From 11.1.10 until 11.4.14 and from 12.0.0-alpha.4 until 12.0.0-alpha.5, sanitizeTranslatedHtml() escapes markup and event-handler text inside an iframe srcdoc value but leaves the srcdoc attribute active. Browsers decode the character references and parse the value as a same-origin nested HTML document, allowing attacker-controlled parameters or translation content placed in srcdoc to execute script when applications enable escapeParameter and render translations as HTML through v-html. Versions 9.14.5 and 10.0.8 are also affected and are no longer supported, while i18n-t rendering is not affected. This issue is fixed in versions 11.4.14 and 12.0.0-alpha.5.

Affected products

intlify vue-i18n: from 11.1.10, < 11.4.14; from 12.0.0-alpha.4, < 12.0.0-alpha.5; = 9.14.5, = 10.0.8

References

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