The lack of sanitization of URLs protocols in the createLink.openLink function enables the execution of arbitrary JavaScript code within the context of the parent page.
https://github.com/FrontFin/mesh-web-sdk/blob/cf013b85ab95d64c63cbe46d6cb14695474924e7/packages/link/src/Link.ts#L441
The createLink.openLink function takes base64 encoded links, decodes them, and then sets the resulting string as the src attribute of an iframe. It’s important to note that the protocol part is not validated, so a payload, which is a valid URL, such as javascript:alert(document.domain)//, can be provided to the function.
yarn install and then yarn startamF2YXNjcmlwdDphbGVydCh3aW5kb3cucGFyZW50LmRvY3VtZW50LmJvZHkuZ2V0RWxlbWVudHNCeVRhZ05hbWUoImgyIikuaXRlbSgwKVsiaW5uZXJIVE1MIl0pLy8= h2 title from the parent pageIt can also be verified via https://paylink.meshconnect.com/?linkToken=amF2YXNjcmlwdDphbGVydCgpLy8=.
This is technically indistinguishable from a real page at the rendering level and allows access to the parent page DOM, storage, session, and cookies. If the attacker can specify customIframeId, they can hijack the source of existing iframes.
If access to the private key is possible or if transactions are tampered with or initialized, in a wallet context, it can result in a critical impact due to loss of funds scenarios.
{
"nvd_published_at": "2025-09-22T19:16:23Z",
"github_reviewed_at": "2025-09-22T21:09:27Z",
"github_reviewed": true,
"cwe_ids": [
"CWE-79"
],
"severity": "HIGH"
}