CVE-2026-106101: Quasar Framework Denial of Service Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-89vp-x45c-52cq",
  "modified" : "2026-10-07T20:23:47Z",
  "published" : "2026-10-07T20:23:47Z",
  "aliases" : [ "CVE-2026-106101" ],
  "summary" : "Quasar Framework: DOM Clobbering in Quasar openURL() SafariViewController Integration Causes Client-Side Denial of Service",
  "details" : "### Summary\n\nA DOM Clobbering vulnerability exists in Quasar's `openURL()` utility when handling the iOS `SafariViewController` bridge.\n\nThe vulnerable implementation only checks whether `window.SafariViewController` exists before invoking it as a native bridge object. An attacker who can inject HTML content containing a named element such as `<a id=\"SafariViewController\">` can cause the browser to expose that element as `window.SafariViewController`.\n\nWhen `openURL()` is later called in an iOS environment, Quasar incorrectly treats the DOM element as the native bridge object and attempts to invoke bridge methods that do not exist, resulting in:\n\n```\nTypeError: window.SafariViewController.isAvailable is not a function\n```\n\nThis can cause client-side denial of service and break navigation-related workflows in Quasar applications.\n\n### Details\n\nQuasar provides the `openURL()` utility to open external URLs. On iOS platforms, this utility supports integration with the native `SafariViewController` bridge.\n\nThe vulnerable code is located in:\n\n```\nui/src/utils/open-url/open-url.js\n````\n\nThe affected logic is:\n\n```javascript\nif (Platform.is.ios && window.SafariViewController !== void 0) {\n  window.SafariViewController.isAvailable(available => {\n    if (available) {\n      window.SafariViewController.show({ url }, noop, reject)\n    }\n  })\n}\n````\n\nThe issue is that Quasar only verifies that `window.SafariViewController` is not `undefined`. It does not verify whether the value is the expected native bridge object or whether required methods such as `isAvailable()` and `show()` are valid functions.\n\nModern browsers expose elements with specific `id` or `name` attributes as properties of the global `window` object. Therefore, attacker-controlled HTML such as:\n\n```html\n<a id=\"SafariViewController\"></a>\n```\n\ncan cause:\n\n```javascript\nwindow.SafariViewController\n```\n\nto resolve to an `HTMLAnchorElement` instead of the expected native bridge object.\n\nWhen Quasar later executes:\n\n```javascript\nwindow.SafariViewController.isAvailable(...)\n```\n\nthe DOM element is incorrectly treated as the bridge object, causing:\n\n```\nTypeError: window.SafariViewController.isAvailable is not a function\n```\n\nThe root cause is insufficient validation of browser-controlled global properties before using them as trusted native bridge objects.\n\nThe vulnerability was verified through the Quasar `QEditor` rendering path. When attacker-controlled HTML content is rendered into the DOM and creates the `SafariViewController` named element, subsequent calls to `openURL()` fail.\n\nAdditional component-level affected paths were identified in `QSelect` and `QChatMessage` when applications enable HTML rendering features and provide attacker-controlled content. These paths require specific application configurations and were not used as the primary end-to-end reproduction.\n\n### PoC\n\n#### Steps to reproduce\n\n1. Render attacker-controlled HTML content through a Quasar HTML rendering component such as `QEditor`.\n2. Insert the following payload:\n```html\n<a id=\"SafariViewController\" href=\"#bridge\">\n  SafariViewController\n</a>\n````\n\n3. Verify that the browser exposes the element as a global property:   \n\n```javascript\nwindow.SafariViewController\n```\n\nThe value resolves to the injected DOM element instead of the expected native bridge object.\n\n4. Trigger a normal workflow that invokes:    \n\n```javascript\nopenURL('https://example.com')\n```\n\n5. Observe the browser console output:    \n\n```\nTypeError: window.SafariViewController.isAvailable is not a function\n```\n\nThe URL opening workflow fails because Quasar attempts to invoke native bridge methods on the DOM element.\n\nThe same underlying issue can also affect other HTML rendering paths such as `QSelect` and `QChatMessage` when attacker-controlled HTML is rendered and the application later calls `openURL()`.\n\n### Impact\n\nThis vulnerability is a client-side DOM Clobbering and type confusion issue affecting Quasar applications that use the iOS `SafariViewController` integration. An attacker who can control HTML content rendered into the application DOM may cause Quasar's `openURL()` functionality to fail by replacing the expected native bridge object with a DOM element through browser named property resolution.\n\nPotentially affected workflows include external URL navigation, OAuth/login redirects, help or documentation links, payment flows, third-party service redirects, and other application actions that rely on URL opening functionality.\n\nThe confirmed impact is client-side denial of service and navigation or workflow disruption. When the vulnerable condition is triggered, Quasar throws an exception while attempting to invoke methods on the clobbered `SafariViewController` object, preventing the expected URL opening behavior.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "quasar"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.32.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.32.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/quasarframework/quasar/security/advisories/GHSA-89vp-x45c-52cq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-106101"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quasarframework/quasar/commit/52d874bf55309dd3656fb02aed033ab025d477ec"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/quasarframework/quasar"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quasarframework/quasar/releases/tag/quasar-v2.32.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-843" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-07T20:23:47Z",
    "nvd_published_at" : "2026-10-06T17:17:24Z"
  }
}