VulnerabilityPublished 28 Oct 2026

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

Affects vue-i18nSource GCVE Database

Mentioned vulnerabilities

CVE-2025-53892

Authoritative record:CVE-2026-118257· High 7.2

Not known to be exploited · CVSS 7.2 High : upgrade to 11.4.14 soon.

Data as of 28 Oct 2026, 22:12 UTC

CVSS 3.1 base score

7.2High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 11.4.14, 12.0.0-alpha.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade vue-i18n and petite-vue-i18n and @intlify/core-base and @intlify/core and @intlify/vue-i18n-core and @intlify/shared to 11.4.14; vue-i18n and petite-vue-i18n and @intlify/core-base and @intlify/core and @intlify/vue-i18n-core and @intlify/shared to 12.0.0-alpha.5.

Affected software

Product	Affected	Fixed in
npmvue-i18n	Affected =9.14.5	Fixed in–
npmvue-i18n	Affected =10.0.8	Fixed in–
npmvue-i18n	Affected >=11.1.10 <11.4.14	Fixed in 11.4.14
npmvue-i18n	Affected >=12.0.0-alpha.4 <12.0.0-alpha.5 =12.0.0-alpha.4	Fixed in 12.0.0-alpha.5
npmpetite-vue-i18n	Affected =9.14.5	Fixed in–
npmpetite-vue-i18n	Affected =10.0.8	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Summary When `escapeParameter` is enabled (`escapeParameterHtml` in the Legacy API), Vue I18n passes the translated string through `sanitizeTranslatedHtml()`. The sanitizer escapes `<` and `>` in attribute values and neutralizes event handler attributes such as `onerror`, but it does not handle the `srcdoc` attribute of `<iframe>`. The value of `srcdoc` is an HTML document: the browser decodes the character references in it and parses the result as a nested document in the same origin. The escaping and the neutralization done by the sanitizer are both character references, so they are undone inside `srcdoc`. This bypasses the fix for CVE-2025-53892 (GHSA-x8qp-wqqm-57ph). ### Details `sanitizeTranslatedHtml()` ([`packages/shared/src/sanitize.ts` in v11.4.13](https://github.com/intlify/vue-i18n/blob/v11.4.13/packages/shared/src/sanitize.ts#L126-L162)) works on the final translated string: 1. It escapes `<`, `>`, `"` and `'` inside quoted attribute values. 2. It rewrites the `on` of event handler attributes to `on`. 3. It replaces `javascript:` URLs in `href`, `src`, `action` and `formaction` with `about:blank`. Inside `srcdoc`, steps 1 and 2 only produce character references, which the browser decodes before parsing the value as a document. Markup inside `srcdoc` therefore survives the sanitizer, with escaping or without it. This can be reached in three ways: - **A parameter inside `srcdoc`.** With a message such as `<iframe srcdoc="{content}"></iframe>`, `escapeParameter` escapes `content` into character references, and the browser decodes them again. - **Markup in a message.** A message that contains an `<iframe srcdoc="...">` keeps it after sanitizing. The documentation asks not to use HTML messages with content from users, but it also says that the sanitizer neutralizes event handlers in the final HTML. - **Together with GHSA-8rc2-428q-7ww3.** When a call passes a list and named values, the named values are not escaped. An `<iframe srcdoc="...">` in a named value then reaches the sanitizer as markup, even with an ordinary message such as `{0} {name}`. ### PoC ```js import { createI18n } from 'vue-i18n' const i18n = createI18n({ legacy: false, locale: 'en', escapeParameter: true, messages: { en: { message: '<iframe srcdoc="<b>x</b>"></iframe>' } } }) console.log(i18n.global.t('message')) // v11.4.13: <iframe srcdoc="<b>x</b>"></iframe> ``` The browser decodes the value and renders `<b>x</b>` as a separate document inside the `<iframe>`, in the same origin as the page. Any markup in that position is parsed the same way. ### Impact Applications are affected when they enable `escapeParameter`, render translations as HTML (for example with `v-html`), and one of the following applies: - an untrusted value is passed as a parameter that the message places inside `srcdoc`, - message content is not fully trusted (for example crowdsourced or stored translations), or - untrusted named values are passed in the same call as a list (GHSA-8rc2-428q-7ww3). An attacker can then run script in the origin of the application (DOM-based XSS), despite the sanitizer. Rendering through `<i18n-t>` is not affected, since it does not render translations as HTML. ### Patches Fixed in 11.4.14 and 12.0.0-alpha.5. The sanitizer now neutralizes the `srcdoc` attribute itself, in the same way as event handler attributes. v9 and v10 are no longer supported and will not be fixed. Please migrate to v11. ### Workarounds - Do not render translations that can contain untrusted content with `v-html`. Use component interpolation (`<i18n-t>`) instead. - Do not put `srcdoc` in translation messages, and do not pass values into it. ### References - [CWE-79](https://cwe.mitre.org/data/definitions/79.html), [CWE-116](https://cwe.mitre.org/data/definitions/116.html) - [GHSA-x8qp-wqqm-57ph](https://github.com/intlify/vue-i18n/security/advisories/GHSA-x8qp-wqqm-57ph) (CVE-2025-53892): the fix that added `sanitizeTranslatedHtml()` - [GHSA-8rc2-428q-7ww3](https://github.com/intlify/vue-i18n/security/advisories/GHSA-8rc2-428q-7ww3): named values are not escaped when a list is also passed - [HTML Standard: the `srcdoc` attribute](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#attr-iframe-srcdoc)

CWE-116Improper Encoding or Escaping of Output (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Parameterization
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
Architecture and Design · Implementation
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
Query Parameterization (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
V14.4.2 (opens in a new tab)
Attack patterns
Cross Zone Scripting (opens in a new tab)
User-Controlled Filename (opens in a new tab)
Web Server Logs Tampering (opens in a new tab)
AJAX Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-116, CWE-79

Technical details

References

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